Answer:
The same amount of energy is required to either stretch or compress the spring.
Explanation:
The amount of energy required to stretch or compress a spring is equal to the elastic potential energy stored by the spring:

where
k is the spring constant
is the stretch/compression of the spring
In the first case, the spring is stretched from x=0 to x=d, so

and the amount of energy required is

In the second case, the spring is compressed from x=0 to x=-d, so

and the amount of energy required is

so we see that the amount of energy required is the same.
Answer:
0 J
Explanation:
As work is force times displacement, if no displacement occurs, no work occurs.
Answer:
See Explanation
Explanation:
Sound is a mechanical wave. A mechanical wave requires a material medium for propagation. This means that sound waves must be carried in air. If there are no air molecules, sound waves can not travel.
When air is gradually removed from the jar by the pump, the sound intensity from the bell gradually decreases owing to the fact that air which is the medium through which sound waves are propagated is gradually being removed from the jar.
If you have a skateboard and you skate into a tree on accident the same amount of force you put onto that tree when you was on the skateboard will come back at you when you bounce back
Answer:
20 m
Explanation:
From the equation of motion,
S = ut+1/2gt²................................. Equation 1
Where S = Height, u = initial velocity, t = time, g = acceleration due to gravity.
Note: Because the rocked is being dropped from a height, acceleration due to gravity is positive (g), and initial velocity (u) is negative
Given: t = 2.0 s, g = 10 m/s², u = 0 m/s (dropped from height)
Substituting into equation 1
S = 0(2) + 1/2(10)(2)²
S = 5(4)
S = 20 m
Hence the height of the the cliff above the pool is 20 m