Answer:
160 kg
Explanation:
f = ma
100 = m * a
a = v/t
v = distanc/time
dist = 40m
time = 8 sec
v = 40/8
a = 40/(64)= 5/8
m = 100*8/5= 160 kg
Describe how acceleration and velocity are related and specify if these are scalar or vector quantities.
While cooking dinner, Dinah's oven uses a 125.6 V line and draws 7.9 A of current
when heated to its maximum temperature. What is the resistance of the oven when
it's fully heated?
Apply ohms law
[tex]\\ \tt\hookrightarrow \dfrac{V}{I}=R[/tex]
[tex]\\ \tt\hookrightarrow R=\dfrac{125.6}{7.9}[/tex]
[tex]\\ \tt\hookrightarrow R=15.8\Omega[/tex]
While cooking dinner, Dinah's oven uses a 125.6 V line and draws 7.9 A of current when heated to its maximum temperature. What is the resistance of the oven when it's fully heated?
✒️ Answer:===================Current=I=7.9AVoltage=V=125.6VResistance=RApply ohms law[tex] \frac{v}{i} = r[/tex]
[tex]r = \frac{125.6}{7.9} [/tex]
[tex]r = 15.8[/tex]
=====================#CarryOnLearningA block of mass
m1 = 4.50 kg
initially at rest on top of a frictionless, horizontal table is attached by a lightweight string to a second block of mass
m2 = 2.70 kg
hanging vertically from the edge of the table and a distance
h = 0.410 m
above the floor (as shown in the figure below). If the edge of the table is assumed to be frictionless, what is the speed with which the first block leaves the edge of the table? (Assume the first block leaves the edge of the table after the second block reaches the floor.)
The speed with which the first block leaves the edge of the table is 2.84 m/s.
Conservation of mechanical energy
Since both blocks are connected, they will travel at the same speed from the given position. The potential energy of the blocks at the given position will be converted to kinetic energy.
P.E = K.E
mgh = ¹/₂mv²
gh = ¹/₂v²
[tex]v = \sqrt{2gh}[/tex]
The speed of the blocks from the given position is calculated as follows;
[tex]v = \sqrt{2 \times 9.8 \times 0.41} \\\\v = 2.84 \ m/s[/tex]
Thus, the speed with which the first block leaves the edge of the table is 2.84 m/s.
Learn more about conservation of mechanical energy here: https://brainly.com/question/6852965
The cheetah is considered the fastest running animal in the world. Cheetahs can accelerate to a speed of 21.5 m/s in 2.50 s and can continue to accelerate to reach a top speed of 28.5 m/s. Assume the acceleration is constant until the top speed is reached and is zero thereafter.
Express the cheetah's top speed in mi/h.
Answer: 63.753 mph
Explanation:
[tex]28.5 \frac{m}{s} * \frac{1 mile}{1609.34 m} * \frac{3600s}{1 hour} = 63.753 \frac{miles}{hour}[/tex]
A 13.0 kg toy train car moving at 3.40 m/s on a straight level train track, collides head-on with a second train car whose mass is 38.0 kg and was at rest on the track. If the collision is perfectly elastic and all motion is frictionless, calculate the velocities of the two cars after the
Before the collision, the total momentum of the two train cars is
(13.0 kg) (3.40 m/s) + 0 = 44.2 kg•m/s
After the collision, the two cars have velocity v₁ and v₂ so that their total momentum is
(13.0 kg) v₁ + (38.0 kg) v₂
Momentum is conserved, so
(13.0 kg) v₁ + (38.0 kg) v₂ = 44.2 kg•m/s
Before collision, the total kinetic energy of the two cars is
1/2 (13.0 kg) (3.40 m/s)² + 0 = 75.14 J
and after collision,
1/2 (13.0 kg) v₁² + 1/2 (38.0 kg) v₂²
Energy is also conserved, so
1/2 (13.0 kg) v₁² + 1/2 (38.0 kg) v₂² = 75.14 J
or
(13.0 kg) v₁² + (38.0 kg) v₂² = 150.28 J
Solve the momentum equation for either v₁ or v₂ :
(13.0 kg) v₁ + (38.0 kg) v₂ = 44.2 kg•m/s
⇒ v₂ = (44.2 kg•m/s - (13.0 kg) v₁) / (38.0 kg)
Substitute this into the energy equation and solve for the other variable :
(13.0 kg) v₁² + (38.0 kg) [(44.2 kg•m/s - (13.0 kg) v₁) / (38.0 kg)]² = 150.28 J
⇒ (17.4 kg) v₁² - (30.2 kg•m/s) v₁ + 51.4 J ≈ 150.28 J
⇒ (17.4 kg) v₁² - (30.2 kg•m/s) v₁ - 98.9 J ≈ 0
Using the quadratic formula,
⇒ v₁ = 3.40 m/s or v₁ ≈ -1.67 m/s
(We ignore the second solution because that's the initial condition.)
Solve for the remaining velocity:
v₂ = (44.2 kg•m/s - (13.0 kg) (-1.67 m/s)) / (38.0 kg)
⇒ v₂ ≈ 1.73 m/s
5. Suppose a space ship traveling at 1000 miles per hour enters an area free of gravitational forces and
free of air resistance. If the pilot wishes to slow the ship down, he can accomplish that by shutting off
the engine for a while.
a. True
b. False
Answer:
False
Explanation:
Unless it encounters external factors, the ship will continue to move at a fixed pace even if the engine is turned off.
PROBLEM 1a. A skier of mass 65 kilograms is at the top of a slope with initial velocity 5 meters/sec. The slope has a vertical descent of 150 meters and is near frictionless. Find the skier's velocity at the bottom of the slope.
Answer:
The skier is in a conservative system, as the only force acting upon him is gravity. Instead of calculating the work done over the curved hills, we can construct an alternate path, because of the principle of path independence:
Explanation:
Spring tides occur when solar and lunar tides are in sync with each other. On the diagram, identify the two moon phases that correspond to a spring tide.
Answer
Sun and Moon's gravity
A transverse wave traveling along a string transports energy at a rate r. If we want to double this rate, we could: _____________
a. increase the amplitude of the wave by a factor of 8.
b. increase the amplitude of the wave by a factor of 4.
c. increase the amplitude of the wave by a factor of 2.
We will increase the amplitude of the wave by a factor of 4 If we want to double this rate
Transverse wave energy travelTransverse wave, travels in a way in which points on a wave oscillate along paths at right angles of 90 degrees to the direction of the wave.
We see that energy transported along a wave path is directly proportional to the square of the amplitude.
E =kA^2
Therefore, we will increase the amplitude of the wave by a factor of 4 If we want to double this rate.
Option B
More on Wave
https://brainly.com/question/3004869
A truck weighing 5 * 10^3 kgf and a cart weighting 500 kgf are moving with the same speed compare their kinetic energies?
A truck weighing 5 x 10³ kg force.
A cart weighing 500 kg force.
Moving with the same speed complete their
kinetic energies.
As we know that,
Formula of:
→ Kinetic energy = 1/2 x m x v².
Using this formula in the equation, we get.
(1).
→ For truck = 1/2 x 5 x 10³ x v².-----
→ For cart = 1/2 x 500 x v². -----(2).
Divide equation (1) and (2), we get.
⇒ KE₁/KE₂ = 5 x 10³/5 x 10².
➡ KE₁/KE₂ = 10/1.
⇒ KE₁/KE₂ = 10:1.
11
A bus travels at 54.0 km h while moving but after accounting for stopping time, to let
passengers on and off the coach, it averages a speed of 45.0 km h. How many minutes does
the bus stop for each hour?
Answer:
10 minutes
Explanation:
Given:
Given:Speed of bus excluding stoppages =54 km/h
Speed of bus including stoppages = 45 km/h
To calculate: Minutes/per hour the bus stopped = ?
Distance covered by bus without stopping =54 km/h
Distance covered by bus with stopping =45 km/h
Due to stoppages it could
9km (54-45km) less
Time taken to cover 9 km=?
time \: taken \: = \frac{distane}{speed }timetaken=
speed
distane
Distance=9km
Speed = 54km/h.
Substituting given values on the above formula we get,
time \: taken \: = \frac{9}{54} hour = \frac{1}{6} hour \:timetaken=
54
9
hour=
6
1
hour
=10 minutes
Hence,the correct answer is 10 minutes.
If you wanted to move an electron from the positive to the negative terminal of the battery, how much work WWW would you need to do on the electron
The work is simply W = V Q where V is the voltage of the battery and Q the charge on the electron
W = V joules/coulomb * E coulombs = joules
2. How do you represent acceleration? How do you decide on the direction of the arrow?
Answer:
velocity arrow
Explanation:
When velocity decreases, acceleration and velocity are in opposite directions, so the acceleration arrow and velocity arrow point in the opposite directions.
Why does air blows from one place to another
Air blows from one place to another because gases move from high-pressure areas to low-pressure areas
In simple words
it happens because of pressure differences.
Answer:
Gases moving from high-pressure places to low-pressure places. The bigger the difference of pressure the faster the air moves from both. Giving the movement of air we experience.
OR:
The high-pressure air will raise up to the low-pressure air and will come down causing the air will blow from one place to another.
What is the strategy you use to solve word problems in physics?
Answer:
The strategy we would like you to learn has five major steps: Focus the Problem, Physics Description, Plan a Solution, Execute the Plan, and Evaluate the Solution. Let's take a detailed look at each of these steps and then do an sample problem following the strategy.
What happens if lightbulb C
burns out?
A. Only lightbulb C turns off.
B. All of the bulbs go out.
C. Lightbulbs B and C turn off, but A stays
on.
Answer:
i think the answer is (a) since c is not responsible for the electricity
What two quantities do you need to know to calculate the numerical value of velocity
You need the distance travelled and how long it took so the time. You can use this in the formula Speed = distance / time to calculate the speed or velocity.
A car starts from rest and accelerate at 9 m/s?. At the end of 240 m long drive, what is its speed.
A car starts from rest and accelerates at 9 m/s². After 240 m. the final speed is 66 m/s.
What is Uniformly Accelerated Motion?Uniformly Accelerated Motion is the motion of an object where the acceleration is constant.
A car starts from rest, that is, its initial speed is 0 m/s. It accelerates at 9 m/s². We can find the final speed after 240 m using the following kinematic equation.
v² = u² + 2 × a × s
v² = (0 m/s)² + 2 × (9 m/s²) × 240 m
v = 66 m/s
where,
v is the final speed.u is the initial speed.a is the acceleration.s is the displacement.A car starts from rest and accelerates at 9 m/s². After 240 m. the final speed is 66 m/s.
Learn more about Uniformly Accelerated Motion here: https://brainly.com/question/10178440
calculate the work done by the person who applies force of 5000N to lift a load up to a height of 2m
Answer:
W = 10000J
Explanation:
W = F • s
W = Work in J
F = Force in N
s = displacement in m
W = 5000N • 2m
W = 10000J
Two wires made of the same Two wires made of the same material are
stretched by equal forces. The second wire
is twice as long as the first one and also has
twice the diameter of the first wire.
If the first wire is stretched by 7.7 cm, then
by how long is the second wire stretched?
The second wire is stretched by 15.4 cm long provided the two-wire are made of the same materials and equal forces.
What is the Young's Modulus of Elasticity?Young's Modulus of Elasticity explains the elastic characteristics of a solid experiencing tension or compression in a unilateral direction
Here, the material used is a wire which returns to its length after being stretched or compressed.
From the parameters given:
There are two wires with the same materials, stretched by equal forces.If the second wire is as twice as first, then:
2x = xwhere;
x = first wire = 7.7 cm2x = second wire = 7.7 cm × 2 = 15.4 cmLearn more about Young's Modulus of Elasticity here:
https://brainly.com/question/7694106
Which of the following best describes the magnetic force?
A. The magnetic force is a noncontact force that acts between two
charged particles.
B. The magnetic force is a contact force that acts between two
magnetic materials.
C. The magnetic force is a noncontact force that acts between two
magnetic materials.
D. The magnetic force is a contact force that acts between two
charged particles.
Answer:
It's C. The magnetic force is a
Explanation:
took the test
A fan converts 4.2 kJ of electrical energy to kinetic energy every minute. The power of the fan is...
The power of the fan is 70 Watt.
What is power?Power can be defined as the rate at which energy is used. The S.I unit of power is Watt (W)
The power of the fan can be calculated using the formula below.
Formula:P = E/t.......................... Eqaution 1Where:P = Power of the fanE = Energy of the fant = time
From the question,
Given:E = 4.2 kJ = 4200 Jt = 1 minutes = 60 seconds.Substitute these values into equation 1
P = 4200/60P = 70 Watt.Hence, The power of the fan is 70 Watt.
Learn more about power here: https://brainly.com/question/3631756
Pretty please help me with this!
Mrs. Kelly is taking her dog, Shadow, for a walk. Shadow sees another dog and gets excited and starts to pull forward. If Shadow weights 25 kilograms and accelerates at 3m/s2, what is the force that Shadow exerts on the leash?
a.) 75 N
b.) 28 N
c.) 25 N
d.) 3 N
Answer:
a.) 75 N
Explanation:
Force = mass × acceleration
Here,
Mass (m) = 25 kg
Acceleration (a) = 3 m/s²
Force (F) = ?
Using the formula,
F = ma
F = 25 × 3
F = 75 N
Hope it helps ⚜
Earth exerts a 100 N gravitational force on a metal box. What is the magnitude of the gravitational force the metal box exerts on Earth? Explain your answer
We have that the magnitude of the gravitational force is mathematically given as
f=6.377N
ForceQuestion Parameters:
Earth exerts a 100 N gravitational force on a metal box.
(Mass of the earth is 6e24 kg and radius of the earth is 6.4e6m.)
Generally the equation for the Gravitational mForce is mathematically given as
[tex]F=\frac{GMm}{r^2}\\\\Therefore\\\\F=\frac{100/9.8* 6e116e24}{6.4e6^2}[/tex]
f=6.377N
For more information on Force visit
https://brainly.com/question/26115859
Choose the correct option.
A metal bar PQ is suspended freely . It always comes to rest with its end Q pointing towards north. Another bar XY of same material settles in no definite direction when freely suspended. The two bars are brought closed together.
Which of the following is true?
a) end Q attracts X but repels Y
b) end Q attracts Y but repels X
c) end Q attracts both ends X and Y
d) end Q repels both ends X and Y
C) end Q attracts both X and Y
Reason: The metal bar PQ is magnetized and has magnetic properties in it, that's I why the point Q is pointing towards the north. The XY bar doesnt point towards any specific direction because it isn't magnetized and doesn't have magnetic properties in it, and that's why it gets attracted by Q and it's both ends.
A Concorde airplane could fly at an average speed of 694 m/s. Calculate how long it would have
taken the Concorde to fly around the world, which is approximately 4.00 x 10^7
Answer:
I actually don't know bc I only need point s so yeah
Explanation:
the explanaition is nothing bc I have nothing
A locomotive is pulling 9 freight cars, each of which is loaded with the same weight. The mass of each loaded car is 37,000 kg, and we can neglect friction on these 9 cars. If the train is accelerating forward at 0.81 m/s^2 on a level track, what is the tension in the coupling between the second and third cars?
The tension in the coupling between the second and third cars is 269,730 N.
Tension in the coupling between the carsSince the weight of each car is the same, the applied force on each will be the same and the tension on the coupling between the cars will be the same.
T = F = ma
T = 9(37,000 x 0.81)
T = 269,730 N
Thus, the tension in the coupling between the second and third cars is 269,730 N.
Learn more about tensional forces here: https://brainly.com/question/2008782
A lightbulb is 3m from a wall. What are the focal length and the position (measured from the bulb) of a lens that will form an image on the wall that is twice the size of the lightbulb?
The focal length of the lens is 2m and the position of the image is 6 m.
Magnification of the imageThe size of the image formed depends on the position of the object from the lens.
[tex]M = \frac{v}{u}[/tex]
where;
M is the magnificationv is the image distanceu is the object distanceImage distanceThe image distance is calculated as follows;
[tex]2 = \frac{v}{3} \\\\v = 2(3) \\\\v = 6 \ m[/tex]
Focal length of the lensThe focal length of the lens is calculated as follows;
[tex]\frac{1}{f} = \frac{1}{v} + \frac{1}{u}\\\\\frac{1}{f} = \frac{1}{6} + \frac{1}{3} \\\\\frac{1}{f} = \frac{3}{6} \\\\f = 2m[/tex]
Learn more about image formed by converging lens here: https://brainly.com/question/22394546
How many valence electrons does each atom have in the Bohr diagrams?
The number of valance electrons in the given Bohr Diagram is 7 electrons each.
What is Bohr diagram?Bohr diagrams depict electrons orbiting the nucleus of an atom in the same way that planets orbit the sun.
Electrons in the Bohr model are depicted as traveling in circles at different shells depending on the element.
We now know that the Bohr Model has some flaws, but it is still widely used because of its straightforward approach to atomic theory.
The Bohr model was also the first to incorporate quantum theory into an atomic model, making it the forerunner of today's more accurate quantum-mechanical models.
Each valance electron in the given Bohr Diagram has 7 electrons.
Thus, the valance electrons in each of the given diagram is 7 electrons as they have these electrons in their outermost shell.
For more details regarding Bohr Diagram, visit:
https://brainly.com/question/28708964
#SPJ2
26) Star A and star B are the same surface temperature. Star A has twice the radius as star B. How does the amount of energy radiated per unit area from the surface of A compare to surface of B?
Answer:
1/4
Explanation:
Total radiation energy depends on temperature, so [tex]E_A=E_B[/tex]
Radius [tex]R_A=2R_B[/tex]
so the surface area [tex]S_A=4 S_B[/tex]
energy per unit area
[tex]\frac{E_A}{S_A}=\frac{1}{4}\frac{E_B}{S_B}[/tex]