# SPH3U Quiz on Energy and Energy Conservation

Document Sample

```					SPH3U Quiz on Energy and Energy Conservation                        Name___________

A. Fill in the blanks with the best response (6 pts)
1. Potential Energy is the energy an object has because of _________
and it is calculated by the formula PE = __________

2. Kinetic Energy is the energy an object has because of __________
and it is calculated by the formula KE = __________

3. The law of conservation of energy states that ________________
________________________________________________________
________________________________________________________
________________________________________________________

B. Solve the following problems – full points for complete solutions (12 pts)

1. A roller coaster of mass “m” accelerates downward from a 20 m
tall hill and then moves through a 15 m loop, as shown in the
diagram. If energy is conserved,
a. find the PE at the top of the first hill (A)
b. find the speed at the bottom of the first hill (B)
c. find the speed at the top of the loop (C)

2. 2. A 55 kg student runs to the edge of a cliff at 3 m/s and jumps
into the icy cold water 12 m below, as shown in the diagram.
Assuming energy conservation,
a. find the total energy (PE and KE) as the student jumps
b. with what speed will the student hit the water?
c. At what height (above the water) will the amounts of PE
and KE be equal?

3. Solve the following problem using both kinematics AND energy
conservation. A 0.5 kg model rocket is shot upward with an initial
speed of 25 m/s. If energy is conserved, determine the maximum
height of the rocket.
d = vit + ½ at2  vf = vi + at  vf2 = vi2 + 2ad