Answer:
1. the pencil would have the momentum and would keep going until it hits the windshield. 2. when the car suddenly accelerates, the pencil would be inert and it would move toward the back of the car until a constant speed from the car is reached.
10mm=1cm
So..........
275 mm=27.5 cm
<span>A rock is dropped from a sea cliff and hits the water 3.2s later. How high is the cliff?
t = sqrt(2y/g)
3.2 = sqrt(2y/9.81)
y = 50.23 m
</span><span>How long would it take sound to travel the same distance?
t = 50.23 / </span><span>343 m/s
t = 0.15 s
</span><span>How long would it take light to travel this distance?
t = 50.23 / </span><span>299 792 458 m / s
t = 1.68x10^-7 s</span>
Answer:

Explanation:
The object is moving to and fro about its mean position
and the equation for its displacement is given as

now in one complete time period we know that the the object will complete its one oscillation
So the change in the position of the object in one complete time period will be ZERO
so here we can say that

since change in position is zero
so displacement = 0

A. A stretched catapult can do work when released so it must have potential energy.
b. A stone on the ground will not move on its own ever again so it has zero energy.
c. In order to roll an object there must be a friction force between the object and the ground (otherwise it will slide)
d. To lift a stone you must overcome the weight which is the force due to gravity.
e. Work and energy are both measured in Joules.