Answer:
Explanation:
<u>Instant Velocity and Acceleration
</u>
Give the position of an object as a function of time y(x), the instant velocity can be obtained by

Where y'(x) is the first derivative of y respect to time x. The instant acceleration is given by

We are given the function for y

Note we have changed the last term to be quadratic, so the question has more sense.
The velocity is

And the acceleration is

1) B. Energy is the ability to do work
2) C. Energy is conserved, it just goes from one form to another.
3) Work = Force x displacement
= 300 x 100 = 30,000 Joules
4) leaning a brick because no displacement is taking place.
5) They change the amount/strength or direction of the force needed.
6) Less force is needed and applied over a longer distance.
7) Heat is the flow of thermal energy from one object to another.
Answer:
A. 20 N
Explanation:
the weight of book is 2×10= 20N
42- C
43- A
44- C
45- A
46- B
47- D
Explanation:
The particle will be at rest when its velocity
is equal to zero. Recall that the velocity is simply the derivative of the position
with respect to time:

Since 
then

Solving for t, we find that the particle will be at rest at
