Answer:
Examples include listening carefully to what someone is saying while ignoring other conversations in a room (the cocktail party effect) or listening to a cell phone conversation while driving a car. Attention is one of the most intensely studied topics within psychology and cognitive neuroscience.
The the figure shows a famous roller coaster ride. You can ignore friction. If the roller coaster leaves Point Q from rest, what is its speed at the top of 25 m peak(Point s
Answer:
22 m/s
Explanation:
PEf +KEf =PE0 +KE0 →PE0 −PEf =KEf
−mgΔy= 1 mv2 →v= −2gΔy = −2(9.8 m/s2)(−25 m)=22 m/s
A peregrine falcon dives at pigeon . the falcon start downward from rest with free-fall acceleration . if the pigeon is 76.0 m below the initial position of the falcon , how long the falcon take to reach the pigeon? Assume that the pigeon remains at rest .
Answer:
3.94 s
Explanation:
Take down to be positive. Given:
Δy = 76.0 m
v₀ = 0 m/s
a = 9.8 m/s²
Find: t
Δy = v₀ t + ½ at²
76.0 m = (0 m/s) t + ½ (9.8 m/s²) t²
t = 3.94 s
5.
State the number of significant digits in each measurement and
express the value in scientific notation.
a. 110 m
f. 20.40 m/s
b. 0.2°C
g0.71 ns
c. 0.090 11 kg
h. 0.06 kg
d. 52.5 X 10 - 3
7040 m
600.0 N
וורן
e.
Answer:
Tanong mo po sa guro mo welcome pasensya need ko po ng point
Find an expression for the kinetic energy of the car at the top of the loop.Express the kinetic energy in terms of m, g, h, and R.
Answer:
K.E₂ = mg(h - 2R)
Explanation:
The diagram of the car at the top of the loop is given below. Considering the initial position of the car and the final position as the top of the loop. We apply law of conservation of energy:
K.E₁ + P.E₁ = K.E₂ + P.E₂
where,
K.E₁ = Initial Kinetic Energy = (1/2)mv² = (1/2)m(0 m/s)² = 0 (car initially at rest)
P.E₁ = Initial Potential Energy = mgh
K.E₂ = Final Kinetic Energy at the top of the loop = ?
P.E₂ = Final Potential Energy = mg(2R) (since, the height at top of loop is 2R)
Therefore,
0 + mgh = K.E₂ + mg(2R)
K.E₂ = mg(h - 2R)
The kinetic energy of the car is expressed as K.E = mg(h - 2R). The energy of the object by the integrity of its movement is understood as kinetic energy.
What is kinetic energy?The energy of the body by the virtue of its motion is known as the kinetic energy of the body. It is defined as the product of half of mass and square of velocity.
The following data is observed from the figure;
K.E₁ = Initial Kinetic Energy = (1/2)mv² = (1/2)m(0 m/s)² = 0
P.E₁ = Initial Potential Energy = mgh
K.E₂ = Final Kinetic Energy at the top of the loop =?
P.E₂ = Final Potential Energy = mg(2R) (since, the height at top of loop is 2R)
According to the law of conservation of energy, total energy is defined as the sum of kinetic energy and potential energy.
Total energy = kinetic energy+potential energy
On applying the law of conservation of energy for top and bottom of the loop;
K.E₁ + P.E₁ = K.E₂ + P.E₂
0 + mgh = K.E₂ + mg(2R)
K.E₂ = mg(h - 2R)
Hence the kinetic energy of the car is expressed as K.E = mg(h - 2R).
To learn more about kinetic energy refer to the link;
brainly.com/question/999862
If 10 calories of energy are added to 2 grams of ice at -30° C, calculate the final temperature of the ice. (Notice that the specific heat of ice is different from that of water.) Assume the specific heat of ice is 0.5
-30° C
40° C
-20° C
30° C
Answer:
-20°C
Explanation:
The specific heat capacity of ice using the cgs system is 0.5cal/g°C
The enthalpy change is calculated as follows
ΔH=MC∅ where M represents mass C represents specific heat and ∅ represents the temperature change.
10cal = 2g×0.5cal/g°C×∅
∅=10cal/(2g×0.5cal/g°C)
∅=10°C
Final temperature= -30°C+ 10°C= -20°C
Answer:
-20 degrees Celsius
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A plane is heading due west and climbing at the rate of 80 km/hr. If its airspeed is 540 km/hr and there is a wind blowing 80 km/hr to the northwest, what is the ground speed of the plane?
Answer:
599.245km/hr
Explanation:
A plane is heading due west and climbing at the rate of 80 km/hr. If its airspeed is 540 km/hr and there is a wind blowing 80 km/hr to the northwest, what is the ground speed of the plane?
We solve the above question using vectors
In vector form Air speed is -540i + 0j Wind speed is (-80/√2)i + (80/√2)j
Vector notation wind speed is given as: -56.5685 i + 56.5685j
The vector for the ground speed of the plane =
-540i + 0j -56.5685i + 56.5685j
= -596.56854249i + 56.5685j
The the ground speed of the plane √[(596.56854249)² + (56.5685)²]
= √359094.021081 km/hr
= 599.24454197 km/hr
Approximately
= 599.245km/hr
A circular disk of radius 2.0 m rotates, starting from rest, with a constant angular acceleration of 20.0 rad/s2. What is the tangential acceleration of a point on the edge of the disk at the instant that its angular speed is 1.0 rev/s?a. 40 m/s2.
b. 79 m/s2.
c. zero m/s2.
d. 120 m/s2.
e. 110 m/s2.
Answer:
Option (a) is correct.
Explanation:
Given that,
The radius of a circular disk, r = 2 m
Angular acceleration, [tex]\alpha =2\ rad/s^2[/tex]
We need to find the tangential acceleration of a point on the edge of the disk at the instant that its angular speed is 1.0 rev/s.
Let a is the tangential acceleration. The relation between the angular acceleration and tengential acceleration. Let it is a.
[tex]a=\alpha r\\\\a=20\times 2\\\\a=40\ m/s^2[/tex]
So, the tangential acceleration is [tex]40\ m/s^2[/tex].
What do these two changes have in common?
baking cookies
making paper from wood
Select all that apply.
A car company wants to ensure its newest model can stop in less than 450 ft when traveling at 60 mph. If we assume constant deceleration, find the value of acceleration (in ft/sec2) that accomplishes this.
Answer:
The value of acceleration that accomplishes this is 8.61 ft/s² .
Explanation:
Given;
maximum distance to be traveled by the car when the brake is applied, d = 450 ft
initial velocity of the car, u = 60 mph = (1.467 x 60) = 88.02 ft/s
final velocity of the car when it stops, v = 0
Apply the following kinematic equation to solve for the deceleration of the car.
v² = u² + 2as
0 = 88.02² + (2 x 450)a
-900a = 7747.5204
a = -7747.5204 / 900
a = -8.61 ft/s²
|a| = 8.61 ft/s²
Therefore, the value of acceleration that accomplishes this is 8.61 ft/s² .
A model of a helicopter rotor has four blades, each 3.4 m in length from the central shaft to the tip of the blade. The model is rotated in a wind tunnel at 550 rev/min. What is the radial acceleration of the blade tip, expressed as a multiple of the acceleration g due to gravity?
A. (5.72 × 104)g
B. (6.23 × 102)g
C. (1.15 × 103)g
D. (2.25 × 103)g
How safe is Wind Energy? Use in your own words.
Answer:
wind energy is safe
Explanation:
because it just is
Answer:
Wind energy isn't perfect, but better than the alternatives. There is a risk of falling off a turbine in maitenence and there are instances where birds fly into the blades, however there are far more casualties as a result of coal and other fossil fuel extraction.
Explanation:
which of the following elements is the most reactive? Chlorine Bromine Fluorine Helium
Answer:
Fluorine is the most reactive
Explanation:
Among the halogens, fluorine, chlorine, bromine, and iodine, fluorine is the most reactive one. It forms compounds with all other elements except the noble gases helium (He), neon (Ne) and argon (Ar), whereas stable compounds with krypton (Kr) and xenon (Xe) are formed.
Which of the following statements describe a perfectly in elastic collision
A) two billiard balls bounce off each other
B) a wad of chewing gum is thrown and sticks to a moving truck
C)Two ice skaters hit each other and fall over in opposite directions
D) a car crashes into a tree and rebounds in the other direction
Answer:
B
Explanation:
during a baseball game you are running home and slide into home plate. However you come up short and you are tagged out. Which force stops you from sliding all the way home? a friction b gravity c pull d push
Answer:1 because
Explanation: it’s pointing to the earth and gravity
Pulls things down to earth
An object of mass 3.00 kg, moving with an initial velocity of 5.05 m/s, collides with and sticks to an object of mass 2.76 kg with an initial velocity of -3.66 m/s. Find the final velocity of the composite object.
Answer:
0.752 m/s
Explanation:
m1 = 3.00kg
u1 = 5.05m/s
m2 = 2.76kg
u2 = -3.66m/s
According to the law of conservation of momentum,
m1u1 + m2u2 = (m1+m2)v
3(5.05) + 2.76(-3.66) = (5.05+2.76)v
15.15 - 9.2736 = 7.81v
5.8764 = 7.81v
v = 5.8764/7.81
v = 0.752m/s
A circuit has a voltage drop of 54.0 V across a 30.0 o resistor that carries a current of 1.80 A. What is the power used by the resistor? Use P = VI.
Answer:
P = 97.2 W
Explanation:
Given that,
Voltage drop, V = 54 V
The resistance of the resistor, R = 20 Ohms
Current, I = 1.8 A
We need to find the power used by the resistor. The formula used to find the power is given by :
P = VI
Putting all the values,
P = 54 V × 1.8 A
P = 97.2 W
So, the power used by the resistor is 97.2 W.
There is gravitational force on the Earth from the Sun, and a gravitational force on the Sun from the Earth. Which pulls harder?
Answer:
They both pull the same amount. For every force there is an equal and opposite force.
Explanation:
It increases, f = ma both mass and acceleration are directly proportional to force so if mass is constant acceleration must increase to increase the force.
Answer:
is that a question?
Explanation:
thankyou for the points
true or false the melting of ice cubes is a exothermic reaction
[tex]\huge\boxed{False}[/tex]
_____________________________________ENDOTHERMIC REACTIONS:Endothermic Reaction are those reactions in which the reactants absorb the energy from their surrounding and forms the product.
_____________________________________How to know endothermic reaction?Those changes in which a substance goes from More-ordered state to less-oredered state are endothermic. Where they change from less ordered to more ordered is exothermic.
More ordered means that the movement of vibration of the particles of the substance is less and the are more close to each other. More to less ordered state is given as,
Solid>Liquid>Gas.
_____________________________________Question:In the question it asks about the melting of the ice cube. Ice cube is a solid, and when it will melt, it will change into the liquid water. As we know that, Solid is more ordered and Liquid is less ordered, and The change from more-ordered to less-ordered is endothermic thus the answer is ENDOTHERMIC.
_____________________________________Best Regards,'Borz'A 20.0 kg box slides up a 12.0 m long incline at an angle of 30.0 degrees with the
horizontal. A force of 150 N is applied to the box to pull it up the incline. The applied
force makes an angle of 10.0 degrees to the incline. The increase in the kinetic energy
of the box is:
Answer:
jus multiply by 69
Explanation:
A 715 kg car stopped at an intersection is rear-ended by a 1490 kg truck moving with a speed of 12.5 m/s. If the car was in neutral and its brakes were off, so that the collision is approximately elastic, find the final speed of both vehicles after the collision.
Answer:
The final velocity of the car is 16.893 m/s
The final velocity of the truck is 4.393 m/s
Explanation:
Given;
mass of the car, m₁ = 715 kg
mass of the truck, m₂ = 1490 kg
initial velocity of the car, u₁ = 0
initial velocity of the truck, u₂ = 12.5 m/s
let the final velocity of the car, = v₁
let the final velocity of the truck, = v₂
Apply the principle of conservation of linear momentum for elastic collision;
m₁u₁ + m₂u₂ = m₁v₁ + m₂v₂
(715 x 0) + (1490 x 12.5) = 715v₁ + 1490v₂
18625 = 715v₁ + 1490v₂ -----equation (1)
Apply one-directional velocity formula;
u₁ + v₁ = u₂ + v₂
0 + v₁ = 12.5 + v₂
v₁ = 12.5 + v₂
Substitute v₁ into equation (1)
18625 = 715(12.5 + v₂) + 1490v₂
18625 =8937.5 + 715v₂ + 1490v₂
18625 - 8937.5 = 715v₂ + 1490v₂
9687.5 = 2205v₂
v₂ = 9687.5 / 2205
v₂ = 4.393 m/s
solve for v₁
v₁ = 12.5 + v₂
v₁ = 12.5 + 4.393
v₁ = 16.893 m/s
a. What frequency is received by a person watching an oncoming ambulance moving at 115 km/h and emitting a steady 753 Hz sound from its siren?
b. What frequency does she receive after the ambulance has passed?
Answer:
A)828.8Hz
B)869.2Hz
Explanation:
Here is a complete question;
What frequency is received by a person watching an oncoming ambulance moving at 115 km/h and emitting a steady 753 Hz sound from its siren? Speed of sound is 345m/s
b. What frequency does she receive after the ambulance has passed?
Vs= speed of the ambulance
, We convert to m/s for unit consistency
= 115 km/h= 115km× 1000m/1m × 1hr/3600s= 31.94m/s
Dopler effect is when observed frequency of wave changes with respect to the source or when observed moves relative to transmitting medium can be expressed as
f'=[ (v + vo)/(v- vs)]*f
=[ (v )/(v- vs)]*f
The sign vo and vs depends on vthe direction of the velocity
f= frequency of ambulance siren= 753Hz
v= speed of sound in air= 345m/s
Vo= speed of observer= 0
A) we are to determine the f' of ambulance as heard by person as ambulance approaching.
To find the frequency f' observed by the person we use the expresion below
Then substitute the values
f'=[ (v )/(v- vs)]*f
=[ (345)/(345-31.94)]×753
= 828.8Hz
B)What frequency does she receive after the ambulance has passed?
To find the frequency f' observed by the person we use the expresion below
Then substitute the values
f'=[ (v )/(v + vs)]*f
=[ (345)/(345 + 31.94)]×753
= 869.2Hz
=
please help, what's the efficiency of the two pulleys
Answer:20cm
Explanation:
A ball is kicked off the ground reaching a maximum height of 60m and lands 80m away. Calculate the initial speed and the angle above the horizontal of the ball when it was kicked
Answer:
36.87°
Explanation:
Given
Maximum height = 60m
Horizontal distance (range) = 80,m
Required
Initial speed U
Angle of launch
To get the speed, we will use the range formula;
R = U √2H/g
80 = U√2(60)/9.8
80 = U√12.25
80 = 3.5U
U = 80/3.5
U = 22.86m/s
Get the angle of launch
Using the formula
Theta = tan^-1(y/x)
y is the vertical distance
x is the horizontal distance
Theta = tan^-1(60/80)
Theta = tan^-1(0.75)
Theta = 36.87°
Hence the angle of launch is 36.87°
A radio station can be heard if the receiver is tuned to a frequency of 6x10^5 Hz. What is the wavelength of the radio waves
5 * 10² m
Explanation:We are Given:
Frequency of the wave = 6 * 10⁵ Hz
Wavelength of the wave:
We know the relation:
c = λν
[where λ (Lambda) is the wavelength ,ν (nu) is the frequency and c is the speed of light ]
3 * 10⁸ m/s= (6 * 10⁵ )* λ [replacing known values]
λ = [tex]\frac{3 * 10^{8}}{6 * 10^{5}}[/tex] [dividing both sides by 6 * 10⁵]
λ = 1/2 * 10³
λ = 1/2 * 10 * 10² [10³ can be rewritten as 10 * 10²]
λ = 5 * 10² m
Therefore, the wavelength of the wave is 5 * 10² m
A rock dropped from a 5 m height accelerates at 10 m/s and strikes the ground 1 s later. If the rock is dropped
from a height of 2,5 m, its acceleration of fall is
Answer:
10 m/s²
Explanation:
The above question simply indicates motion under gravity.
The acceleration due to gravity (i.e acceleration of free fall) has a constant value of 10 m/s².
Whether the rock is dropped from a height of 5 m or 2.5 m, it will accelerate at 10 m/s² before striking the ground. The only thing that will be different is the time taken for the rock to strike the ground when released from both 5 m and 2.5 m.
Thus, the rock will have a constant acceleration of 10 m/s² irrespective of the height to which it was released.
Since acceleration due to gravity is a constant, the acceleration of the rock dropped from the 5 m height is the same as that dropped from the 2.5 m height and is equal to 10 m/s²
What is the acceleration due to gravity?Acceleration due to gravity is the acceleration a body falling freely from a height above the earth surface which a body experiences due to the gravitational force of attraction of the earth on the body.
Acceleration due to gravity has a constant value which is equal to 10 m/s².
Therefore, the acceleration of the rock dropped from the 5 m height is the same as that dropped from the 2.5 m height and is equal to 10 m/s².
Learn more about acceleration due to gravity at: https://brainly.com/question/11873969
2) What does the specific heat capacity of a material tell you about how easy it is to heat up
that material
Answer:
High specific heat -> takes more energy to raise/lower object's temperature
Low specific heat -> takes less energy to raise/lower object's temperature
Explanation:
The specific heat capacity is the amount of heat required to raise the temperature of something per unit of mass.
A high specific heat value for an object means it takes more energy to raise or lower that object's temperature. A low specific heat value for an object means it does not take very much energy to heat or cool that object.
A simple pendulum has a period T on Earth. If it were used on Planet X and found to have a period of only 71% of T, what would be the free fall acceleration due to gravity on this planet X?
Answer:
gₓ = 1.4 g = 13.8 m/s²
Explanation:
The time period of simple pendulum on earth is given as:
T = 2π√(L/g)
where,
L = Length of pendulum
g = acceleration due to gravity on the surface of earth = 9.8 m/s²
T = Time Period on Earth
but, on the other planets, it becomes:
Tₓ = 2π√(L/gₓ)
where,
Tₓ = Time Period on Surface of Other Planet
gₓ = acceleration due to gravity on other planet = ?
It is given that:
Tₓ = 71% of T
Tₓ = 0.71 T
using values:
2π√(L/gₓ) = (0.71) 2π√(L/g)
√(1/gₓ) = (0.71)√(1/g)
squaring both sides:
1/gₓ = 0.71/g
gₓ = g/0.71
gₓ = 1.4 g = 13.8 m/s²
A boy of mass 40kg while running develops a momentum of 180Ns. Calculate the velocity of the boy
Answer:
[tex]\boxed {\boxed {\sf v= 4.5 \ m/s}}[/tex]
Explanation:
The formula for momentum is:
[tex]p=mv[/tex]
(p is momentum, m is mass, and v is velocity)
Let's rearrange the formula for velocity, or v.
[tex]\frac{p}{m} =v[/tex]
Velocity can be found by dividing the momentum by the mass.
The momentum is 180 kilograms meter per second. The mass of the boy is 40 kilograms.
[tex]p=180 \ kg*m/s \\m=40 kg[/tex]
Substitute the values into the formula.
[tex]v=\frac{180 \ kg*m/s}{40 \ kg}[/tex]
Divide. Note that the kilograms or "kg" will cancel each other out.
[tex]v=\frac{180 \ m/s}{40 }[/tex]
[tex]v= 4.5 \ m/s[/tex]
The velocity of the boy is 4.5 meters per second.
he gravitational force between two objects of masses m1m1m_1 and m2m2m_2 that are separated by distance rrr is
Answer:
[tex]F = \frac{6.67408m_1 m_2}{10^{11}r^2}[/tex]
Explanation:
Given
[tex]Object_1 = m_1[/tex]
[tex]Object_2 = m_2[/tex]
[tex]Distance = r[/tex]
Required
Determine the force of attraction
This is calculated as:
[tex]F = \frac{GMm}{d^2}[/tex]
Where
M = mass of object 1
m = mass of object 2
d = distance
Where G = gravitational constant
[tex]G = 6.67408 * 10^{-11}\ m^3 kg^{-1} s^{-2}[/tex]
Substitute these values in
[tex]F = \frac{GMm}{d^2}[/tex]
[tex]F = \frac{6.67408 * 10^{-11} * m_1 * m_2}{r^2}[/tex]
[tex]F = \frac{6.67408 * m_1 * m_2* 10^{-11}}{r^2}[/tex]
[tex]F = \frac{6.67408m_1 m_2* 10^{-11}}{r^2}[/tex]
[tex]F = \frac{6.67408m_1 m_2}{10^{11}*r^2}[/tex]
[tex]F = \frac{6.67408m_1 m_2}{10^{11}r^2}[/tex]