Answer: True
Explanation:
As the spring is compressed, it acumulates energy, and the spring "wants to release that energy". This acumulated energy, (potential energy) is called "elastic potential energy" because of the elastical nature of the spring, that when compressed it wants to return to the original shape. So the sentence is true
Answer:
0.00903 rad
0.00926 rad
6.268\times 10^{-6}
Explanation:
s = Diameter of the object
r = Distance between the Earth and the object
Angle subtended is given by

For the Moon

The angle subtended by the Moon is 0.00903 rad
For the Sun

The angle subtended by the Sun is 0.00926 rad
Area ratio is given by

The area ratio is 
Answer:
21.21 m/s
Explanation:
Let KE₁ represent the initial kinetic energy.
Let v₁ represent the initial velocity.
Let KE₂ represent the final kinetic energy.
Let v₂ represent the final velocity.
Next, the data obtained from the question:
Initial velocity (v₁) = 15 m/s
Initial kinetic Energy (KE₁) = E
Final final energy (KE₂) = double the initial kinetic energy = 2E
Final velocity (v₂) =?
Thus, the velocity (v₂) with which the car we travel in order to double it's kinetic energy can be obtained as follow:
KE = ½mv²
NOTE: Mass (m) = constant (since we are considering the same car)
KE₁/v₁² = KE₂/v₂²
E /15² = 2E/v₂²
E/225 = 2E/v₂²
Cross multiply
E × v₂² = 225 × 2E
E × v₂² = 450E
Divide both side by E
v₂² = 450E /E
v₂² = 450
Take the square root of both side.
v₂ = √450
v₂ = 21.21 m/s
Therefore, the car will travel at 21.21 m/s in order to double it's kinetic energy.
Answer:
The momentum would be doubled
Explanation:
The magnitude of the momentum of the freight train is given by:

where
m is the mass of the train
v is its speed
In this problem, we have that the speed of the train is unchanged, while the mass of the train is doubled:

therefore, the new momentum is

so, the momentum has also doubled.