An object is dropped from a 42 m tall building. How long does it take to reach the ground?

Answers

Answer 1

Answer:

2.1 seconds

Explanation:

let D represent the height in meters

let g represent gravity in meters per second squared

let t represent time in seconds

D= -42 meters (negative because it falls down)

g= -9.8m/s^2

t= [tex]\frac{-42 meters}{9.8 m/s^2}[/tex]

this gives t= 4.2857 s^2

the meter units cancel out in the division

now we must simplify the units to singular seconds so...

[tex]\sqrt{4.3 s^{2} }[/tex] which simplifies to [tex]\sqrt{4.3}[/tex] x [tex]\sqrt{s^{2} }[/tex]

this equals 2.1 seconds


Related Questions

Find the area of the given figure

Answers

Answer:

77 sq.cm

Explanation:

Solution,

Trapezium

Perpendicular (P1)=8cm

Perpendicular(P2)=14cm

height(h)=7cm

Now,

We know that,

Area(A)= 1/2 ×h (P1+P2)

= 1/2 × 7cm (8cm+14cm)

= 1/2 × 7cm(22cm)

= 1/2 × 154 squarecm

=77 sq.cm

If you have a train traveling 750 m in 63
seconds how fast is the train travelling?

Answers

Answer:

The train would be moving 47,250 mph

Calculate Kylie’s weight at 3 radii away from the center of the earth. Kylie weighs 565.4N on the earths surface

Answers

Answer:

Earth's mass is 5.98 x 1024 kg and has a radius of 6.37 x 106 m. 8.06 N/kg ... what would be the weight of a 70.0-kg student on the surface of Jupiter?Explanation:

what is the unit of measurement for expressing the intensity of sound

Answers

Decibel - the decibel is a relative unit of measurement equal to one 10th of a bel

An engine has an energy input of 125 J, and 35 J of that energy is transformed into useful energy. What is the efficiency of the engine? 28% 35% 72% 90%.

Answers

The efficiency of the engine at the given useful energy and input energy is 28%.

The given parameters:

Input energy of the engine, = 125 JUseful energy of the engine, 35 J

The efficiency of the engine is defined as the ratio of the output energy (useful energy) to the input energy and it is calculated as follows;

[tex]efficiency\ = \frac{0ut put \ energy}{1nput \ energy} \times \ 100\%\\\\efficiency\ = \frac{35}{125} \times 100\%\\\\efficiency\ = 28 \ \%[/tex]

Thus, the efficiency of the engine at the given useful energy and input energy is 28%.

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Answer:

ITS A

Explanation:

A green ball is dropped from rest from an elevated position at the same instant that a red ball is launched horizontally (from the same height), which ball will hit the ground first? Assume the balls behave as projectiles.
a. green ball
b. red ball
c. the red and green ball will hit the ground at the same time
d. not enough information given

Answers

Answer:

c. the red and green ball will hit the ground at the same time

Explanation:

if two objects are the same size but one is heavier, the heavier one has greater density than the lighter object. Therefore, when both objects are dropped from the same height and at the same time, the heavier object should hit the ground before the lighter one.

True or false? Gas pressure is caused by molecules in a gas colliding with the walls of their container.

Answers

Answer:True

The number of molecules hitting the unit surface per unit time increasethe gas pressure increases.

Answer very true yep

A firecracker is placed in the middle of a room. When the firecracker explodes the parts of the firecracker scatter in all different directions. The total combined momentum of all the parts of the firecracker added together after the explosion must be



A.
more than before the explosion.

B.
less than before the explosion.

C.
can not tell from the given information

D.
the same as before the explosion.

Answers

Because momentum is a vector quantity, the total combined momentum of all the parts of the firecracker added together after the explosion must be the same as before the explosion. The correct answer is D

Given that a firecracker is placed in the middle of a room. This means that the firecracker is at rest. That is its momentum is equal to zero. When the firecracker is lit up, it will move in a certain velocity before it explodes. Since the total combined momentum of all the parts of the firecracker scatter in all different directions are considered, that is added up, then momentum will always be conserved. That is,

The momentum of an object before explosion will always be equal to the momentum of the object after explosion.

Because momentum is a vector quantity, in which we must consider it magnitude and direction, the best answer to this question is option D.

That is,

The total combined momentum of all the parts of the firecracker added together after the explosion must be the same as before the explosion

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Which statement regarding characteristics of electromagnetic radiation is correct?


Longer wavelengths of light have higher energies.

Lower frequencies of light have higher energies.

Higher frequencies of light have shorter wavelengths.

Shorter wavelengths of light have lower energies.

Answers

Answer:

Higher frequencies of light have shorter wavelengths.

Anyone please.??????​

Answers

Answer:

468.42572 Wavelength In Metres

Explanation:

Answer:

[tex]\huge\boxed{\sf Wavelength= 470\ m}[/tex]

Explanation:

Given Data:

Speed of light = c = 3 × 10⁸ m/s (Constant)

Frequency = f = 640 kHz = 6.4 × 10² × 10³ Hz = 6.4 × 10⁵ Hz

Required:

Wavelength = λ = ?

Formula:

λ = c / f

Solution:

λ = 3 × 10⁸ / 6.4 × 10⁵

λ = 0.47 × 10³

λ = 4.7 × 10² m

λ = 470 m

[tex]\rule[225]{225}{2}[/tex]

Hope this helped!

~AH1807

write of the following does not represent electrical power in a circuit ?

(a) I²R


(b) IR²

(c)VI

(d) V²/R​

Answers

(b) IR^2 does not represent electrical power in a circuit.


The equations for electrical power are as follows:

P=I^2R

P=VI

P=V^2/R
(You can get this equation by rearranging V=IR, making I the subject to get I=V/R and substituting that into P=VI)

P=E/T

The solar mass of the Sun is 1. The orbital period of Jupiter is 11. 9 Earth years. What is the distance between Jupiter and the Sun? 5. 2 AU 41 AU 52 AU 410 AU.

Answers

The distance between Jupiter and the sun is 5.2 AU.

According to Kepler's third law, the square of the period of revolution of planets is proportional to the cube of their mean distances from the sun. From this; T^2 = r^3.

Now, we are told that the orbital period (T) is 11. 9 Earth years. We have to make the distance the subject of the formula.

r =T^2/3

r = (11.9)^2/3

r = 5.2 AU

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Answer:

The answer is A. 5.2 AU

Explanation:

in jus dat ni ni fr

A bullet of mass M1 is fired towards a block of mass m2 initially at rest at the edge of a frictionless table of height h as in the figure. The initial speed of the bullet is vi . Consider two cases, a completely inelastic one and an elastic one,where the bullet bounces off the block. inelastic case elastic case a bullet inside no bullet inside A B A' B' What is the ratio of the flight time; i.e., tAB tA′B′ ?

Answers

The ratio of time of flight for inelastic collision to elastic collision is 1:2

The given parameters;

mass of the bullet, = m₁mass of the block, = m₂initial velocity of the bullet, = u₁initial velocity of the block, = u₂

Considering inelastic collision, the final velocity of the system is calculated as;

[tex]m_1u_1 + m_2u_2 = v(m_1 + m_2)\\\\m_1u_1 + 0 = v(m_1 + m_2)\\\\v= \frac{m_1u_1}{m_1 + m_2} \ -- (1)\\\\[/tex]

The time of motion of the system form top of the table is calculated as;

[tex]v = u + gt\\\\v = 0 + gt\\\\v = gt\\\\t= \frac{v}{g} \\\\t_A = \frac{m_1u_1}{g(m_1 + m_2)} \ \ ---(2)[/tex]

Considering elastic collision, the final velocity of the system is calculated as;

[tex]m_1u_1 + m_2 u_2 = m_1v_1 + m_2v_2\\\\m_1u_1 + 0 = m_1v_1 + m_2v_2\\\\m_1 u_1 = m_1v_1 + m_2v_2[/tex]

Apply one-directional velocity

[tex]u_1 + (-v_1) = u_2 + v_2\\\\u_1 -v_1 = 0 + v_2\\\\v_1 = v_2 -u_1[/tex]

Substitute the value of [tex]v_1[/tex] into the above equation;

[tex]m_1u_1 = m_1(v_2 - u_1) + m_2 v_2\\\\m_1u_1 = m_1v_2 -m_1u_1 + m_2v_2\\\\2m_1u_1 = m_1v_2 + m_2v_2\\\\2m_1u_1= v_2(m_1 + m_2)\\\\v_2 = \frac{2m_1u_1}{m_1+ m_2} \ --(3)[/tex]

where;

[tex]v_2[/tex] is the final velocity of the block after collision

Since the bullet bounces off, we assume that only the block fell to the ground from the table.

The time of motion of the block is calculated as follows;

[tex]v_2 = v_0 + gt\\\\v_2 = 0 + gt\\\\t = \frac{v_2}{g} \\\\t_B = \frac{v_2}{g} \\\\ t_B = \frac{2m_1u_1}{g(m_1 + m_2)} \ \ ---(4)[/tex]

The ratio of time of flight for inelastic collision to elastic collision is calculated as follows;

[tex]\frac{t_A}{t_B} = \frac{m_1u_1}{g(m_1 + m_2)} \times \frac{g(m_1 + m_2)}{2m_1u_1} \\\\\frac{t_A}{t_B} = \frac{1}{2} \\\\t_A:t_B = 1: 2[/tex]

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pls help quickly

Which of these materials best scatters the light that strikes it?
a pure water
b shiny mirror
c frosted glass
d eyeglass lens

Answers

Answer: frosted glass

Explanation:

Answer:

C

Explanation:

Frosted Glass

Two 3.0g bullets are fired with speeds of 40.0 m/s
and 80.0 m/s, respectively. What are their kinetic
energies? Which bullet has more kinetic energy? What is the ratio of their kinetic energies?

Answers

Two 3.0g bullets are fired with speeds of 40.0 m/s and 80.0 m/s, respectively. Mass of the 1st bullet (m1) = 3 g = 0.003 KgMass of the 2nd bullet (m2) = 3 g = 0.003 KgVelocity of the 1st bullet (v1) = 40 m/sVelocity of the 2nd bullet (v2) = 80 m/sWe know, kinetic energy of a body

[tex] = \sf \frac{1}{2} m {v}^{2} [/tex]

Kinetic energy of the 1st bullet [tex] \sf = \frac{1}{2} \times m1 \times {(v1)}^{2} \\ \sf= \frac{1}{2} \times 0.003 \times {(40)}^{2}J \\ \sf = \frac{1}{2} \times 0.003 \times 1600J \\ \sf = 2.4J[/tex]Kinetic energy of the 2nd bullet [tex] \sf = \frac{1}{2} \times m2 \times {(v2)}^{2} \\ \sf= \frac{1}{2} \times 0.003 \times {(80)}^{2}J \\ \sf = \frac{1}{2} \times 0.003 \times 6400J \\ \sf = 9.6J[/tex] So, the 2nd bullet which has greater velocity has more kinetic energy.Therefore, the ratio of their kinetic energies

[tex] \sf = \frac{2.4J}{9.6J} \\ \sf= \frac{24}{96} = \frac{1}{4} \\ \sf = 1 : 4[/tex]

Answer:

The kinetic energies of the bullets are 2.4 J and 9.6 J.

The bullet having greater velocity has more kinetic energy.

The ratio of their kinetic energies is 1 : 4.

Hope you could get an idea from here

Doubt clarification - use comment section.

The kinetic energy of the two bullets are 2.4 J and 9.6 J respectively.

The ratio of the kinetic energy of the bullets is 1:4.

What is kinetic energy?

The kinetic energy of an object is the energy possessed by the object due to its motion.

The kinetic energy of the two bullets is calculated as follows;

[tex]K.E_1 = \frac{1}{2} \times 0.003 \times 40^2 = 2.4 \ J\\\\K.E_2 = \frac{1}{2} \times 0.003 \times 80^2 = 9.6 \ J[/tex]

Ratio of the kinetic energy of the bullets is calculated as follows;

[tex]K.E_1 : K.E_2 = 2.4: 9.6 \ = \ 1: 4[/tex]

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ASAP!!! Imagine you are about to purchase a new refrigerator. There are two models that you are considering. Each
refrigerator is required to have an energy efficiency sticker on the door so that the buyer can be aware of the
cost of running the refrigerator. Refrigerator (A) costs $10.00 a month to operate and $700.00 to buy.
Refrigerator (B) costs $15.00 a month to run and $600.00 to buy. Decide which refrigerator you would purchase,
(A or B) and indicate in the answer box why it would be better for the environment

Answers

Answer:

model A

Explanation:

model A is more expensive to buy but you pay less per month to run it making it a better purchase in the long run. The cheaper cost of running it is better for the environment due to there being less electricity needed to power it.

A car starts with a velocity of 16 m/s and slows at a constant rate of -2m/s2, what is its velocity after 3 s?

Answers

After 3 seconds, the car slows down to

16 m/s + (-2 m/s²) (3 s) = 16 m/s - 6 m/s = 10 m/s

A pilot wishes to fly from airport A to airport B. Airport B is located due south from airport A. The pilots aircraft averages a speed of 160 mi/hr. If the pilot is flying in a wind which blows out of the west at a speed of 40 mi/hr, then the pilot should head his plane in the direction of vector ...

Answers

The pilot should head his plane in the direction of vector of 76⁰.

The given parameters;

velocity of the plane due south, a =160 mphvelocity of the wind west, b = 40 mph

Let the direction of the vector = θ

The direction of the vector can be determined by applying the principle of vector addition;

[tex]tan(\theta) = \frac{v_y}{v_x} \\\\\theta = tan^{-1} (\frac{160}{40} )\\\\\theta = 76 \ ^0[/tex]

Thus, the pilot should head his plane in the direction of vector of 76⁰.

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Which element forms more com-
pounds than all the other elements
combined?

Answers

Answer:

Terms in this set (7) Which element forms more compounds than all the other elements combined? Carbon.

Explanation:

Hope its helps you ✌️

A payload of mass m, where m

Answers

Answer:

where m < M is delivered to the space station. Soon after, the space station's orbit is adjusted so that it is 50 km ...

A payload of mass m, where m<M, is delivered to the space station.

What is payload?

The maximum mass that the vehicle is capable of moving is referred to as the mass's payload. The carrying capacity of a packet or other transmission data unit is referred to as a payload.

The phrase, which has military roots, is frequently used in relation to malicious code that can be executed and cause harm. A payload is a section of code that runs when hackers take advantage of a weakness. In other words, it's a module for an exploit.

It typically consists of a few commands that will execute on the targeted operating system in order to steal data and carry out other malicious deeds (such as keyloggers).

Therefore, A payload of mass m is sent to the space station, where m<M.

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I need help!
A car has a mass of 1,200 kg and the road can provide a maximum force of 24 kN on the car what is the maximum acceleration?

Answers

Answer:

The acceleration of the car with the mass of 1200kg and a force of 11 × 10³N is 9.17m/s²

Explanation:

The gravitational force on Mars is about 38% of Earth. What would a cat weighing 15 pounds on Earth weigh on Mars?

Answers

Answer: 5.7

Explanation: 38% of 15.

The weight we experience ourselves and the ability to stand in the ground is due to the gravitational pull of earth. If this pull is lower we feel weight loss. So the cat will have a weight of 5.7 pounds or 2.58 kg in mars where the gravitation is about 38% of earth.

What is gravitational force?

Gravitational force is a kind force by which a body attracts other objects into its centre of mass. Earth have strong gravitational effect on objects and thus we are all standing on the surface and everything falling from a height hits the ground.

As the mass of the object increases, gravitational effect also increases. The weight experienced by a body is the product of its mass and gravity. Thus massive body have greater weight.

Our mass is constant everywhere but weight will change according a change in gravity. Mars  have only 38% of gravity of earth. Thus the cat weighing 15 pounds on earth will loss its weight in mars by 38%.

Thus, 15 × 38/100= 5.7 pounds will be the weight of the cat in mars.

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If your friend was on a skateboard and you pushed them with forward (away from your) with a force of 15N, would you feel a force? If so, how much and what direction? *

Answers

Yes. Newton’s third law of motion states every action has an equal and opposite reaction. You would feel a force of 15 N and you would go backwards. This is all assuming you were on a skateboard or were on something where you could move.

Yes.  you would feel a force 20 N towards backward direction due to this.

What is force?

The definition of force in physics is: The push or pull on a massed object changes its velocity.

An external force is an agent that has the power to alter the resting or moving condition of a body. A spring balance can be used to calculate the Force. The Newton is the SI unit of force.

"When one body exerts a force on the other body, the first body experiences a force that is equal in size in the opposite direction of the force which is exerted," according to Newton's third law of motion.

Hence, according to Newton's third law of motion, when you pushed them with forward (away from your) with a force of 15N, you would feel a force of equal magnitude (20 N) in opposite direction (backward direction).

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i do believe that i need help

Answers

WHAT IS THAT omg Helpppp

In a car engine, fuel is ignited within a cylinder to cause an explosion that moves a piston. If the explosion exerts 300 Pa of pressure on a piston with a surface area of 80 cm^2?

Answers

The force exerted by the explosion on the piston is 2.4 N.

The given parameters:

Pressure of the explosion on piston, P = 300 Pa (N/m²)Surface area of the piston, A = 80 cm²

The force exerted on the piston by the explosion is calculated as follows;

F = PA

where;

A is the area of the piston in m²

The surface area of the piston in square meter is calculated as follows;

[tex]A = 80 \ cm^2 \times \frac{(1m)^2}{(100 \ cm)^2} \\\\A = 0.008 \ m^2[/tex]

The force exerted by the explosion on the piston is calculated as follows;

[tex]F = 300 \ (N/m^2)\ \times \ 0.008 \ (m^2)\\\\F = 2.4 \ N[/tex]

The complete question is here:

In a car engine, fuel is ignited within a cylinder to cause an explosion that moves a piston. If the explosion exerts 300 Pa of pressure on a piston with a surface area of 80 cm^2, what is the force exerted on the piston?

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a measure of change in velocity in a measure of time is

Answers

[tex]\\ \sf\Rrightarrow Acceleration=\dfrac{\Delta V}{t}[)tex]

In simplified form

[tex]\\ \sf\Rrightarrow Acceleration=\dfrac{dv}{dt}[/tex]

The rate of change of velocity with respect to time period is called acceleration.SI units-m/s^2

A vertical spring stretches 9.6 cm when a 1.3 kg block is hung from its end. (a) Calculate the spring constant. This block is then displaced an additional 5.0 cm downward and released from rest. Find the (b) period, (c) freque

Answers

Answer:

F = - K x

a) K = 1.3 kg * 9.8 m/s^2 / .096 m = 133 kg/sec^2

b)  ω = (K/m)^1/2     angular frequency of SHM

ω = (133 / 1.3)^1/2 = 10.1 / sec

f = 2 π ω = 6.28 * 10.1 / sec = 63.5 / sec

P = 1/f = .0157 sec

car was moving in a straight road of length 320 km it covered 240 km with an average velocity 75 km/hr then it ran out of fuel and stopped for 0.6 hr until it was refueled and completed its journey with a velocity 100 km/hr so the average velocity during the whole journey

Answers

The average velocity of the car for the whole journey is 69.57 km/h.

The given parameters:

Length of the road, L = 320 kmDistance covered = 240 km at 75 km/htime spent refueling, t₂ = 0.6 hrFinal velocity, = 100 km/hr

The time spent by the before refueling is calculated as follows;

[tex]t = \frac{d}{v} \\\\t_1 = \frac{240}{75} \\\\t_1 = 3.2 \ hours[/tex]

The time spent by the car for the remaining journey;

[tex]t_3 = \frac{320 - 240}{100} \\\\t_3 = 0.8 \ hr[/tex]

The total time of the journey is calculated as follows;

[tex]t = t_1 + t_2 + t_3\\\\t = 3.2 \ hr \ + \ 0.6 \ hr \ + \ 0.8 \ hr\\\\t = 4.6 \ hours[/tex]

The average velocity of the car for the whole journey is calculated as follows;

[tex]v = \frac{total \ distance }{total \ time} \\\\v = \frac{320}{4.6} \\\\v = 69.57 \ km/h[/tex]

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What important role does each play in an exercise regiment?

Answers

Answer: There are five principles of fitness out of which two are overload principle and rest and recovery principle. Overload principle is one of the most important principle which tell that to gain and improve the fitness one should do the hard work.  

Slowly and gradually the intensity and time of exercise are increased so that our body can adapt to the hard work. Overload principle plays an important role in improving the skills and improving performance during exercise and sports.

Rest and recovery principle is important to relax the body and release the stress that happens due to intense training like in case of weight lifting one day rest should be taken to repair and rebuild the muscles. This allows the body to encounter the fatigue and improve performance.

Explanation:

The practice of science can answer only scientific questions. And scientific questions guide the design of investigations. What must be true of the possible answers to a scientific question? A. They are popular with a majority of scientists. B. They agree with all prior experiments. O C. They can be supported by evidence. O D. They lead to increased funding of scientific research.​

Answers

Answer:

They must be supported by evidence.

Explanation:

Every scientific theory or scientifc claim must have scientific evidence.

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This is my question pls help!!! Find the circumference of a circle with a radius of 2.4 m Haynes High School chartered buses for 60 students to go on a field trip. Valley High School chartered buses for 80 students.*The total cost of the buses was the same for the two schools*Students from Valley High School paid $5 less than students from Haynes High School.What was the cost per student for Haynes High School?A. $5 B. $15 C. $20 D. $40 If 9 out of 20 candies are orange, how many orange candies will there be per 100 candies total? David Gain is the chief executive officer (CEo) of Forest Media Corp., which is interested in acquiring RS Communications, Inc. To initiate negotiations, Gain meets with RS's CEo, Gill Raz, on Friday, July 12. Two days later, Gain phones his brother, Mark, who buys 3,800 shares of RS stock on the following Monday. Mark discusses the deal with their father, Jordan, who buys 20,000 RS shares on Thursday. on July 25, the day before the RS bid is due, Gain phones his parents' home, and Mark buys another 3,200 RS shares. over the next few days, Gain periodically phones Mark and Jordan, both of whom continued to buy RS shares. on August 5, RS refuses Forest's bid and announces that it is merging with another company. The price of RS stock rises thirty percent, increasing the value of Mark's and Jordan's shares by nearly $660,000 and $400,000, respectively. Required:a. Is Gain guilty of insider trading?b. Could a court hold Gain liable? Why or why not? enjoy these pictures of Liminal places (strangely familiar places)its really cool and creepy at the same time Select the correct answer.Triangle ABC is reflected across the yaxls and then dilated by a factor of 2 centered at the origin. Which statement correctly describes theresulting Image, triangle DEF? Someone help me with this please, I really need help, and it's due tmrw...PLEASE Which technological inventions are major sources of greenhouse gases? wind turbines ,nuclear power plants, tidal energy converters ,solar panels ,automobiles Which group shown in this figure contains the highest biodiversity Determine the value of cos 45 X 29 What figure of speech would I be adding to a text if I wanted the reader to"hear" the text? *A. SimileB. HyperboleC. SymbolismD. Onomatopoeia find the perimeter of a regular pentagon with each side measuring 6cm. The term commonly used in accounting to describe the format for recording a transaction is:. This is an urgent matter! Please help! someone pls pls help Your family ismoving. A rental truckcosts $40, plus $0.15 forevery mile driven. Writean equation torepresent the totalcost, c, of the movingtruck. A 0.500-g sample containing Na2CO3 plus inert matter is analyzed by adding 50.0 mL of 0.100 M HCl, a slight excess, boiling to remove CO2, and then back-titrating the excess acid with 0.100 M NaOH. If 5.6 mL NaOH is required for the back-titration, what is the percent Na2CO3 in the sample? Makayla wants to spend no more than $50 to celebrate her birthday with her four friends. Each box of her favorite pizza costs $7.50. Which inequality can Makayla use to find p, the number of boxes of pizza she can buy without exceeding $50?F.7.5p > 50G.50p7.50H.7.5p < 50J.p + 7.5 < 50 Multiply the fractions and reduce to lowest terms: 3/4 x 1/3