Download Energy Review Guide Kinetic and Potential Energy 1) A baseball

Energy Review Guide
Name: _________________________________
Kinetic and Potential Energy
1) A baseball (0.145 kg) is flying through the air at
a velocity of 23 m/s at a height of 12 m.
a. What is the baseball’s kinetic energy?
3) If a baseball undergoes the following changes,
what would happen to its overall kinetic
energy?
a. Baseball’s mass triples
b. Baseball’s velocity quadruples
b. What is the baseball’s potential energy?
c. Baseball’s velocity halves
c. What is the baseball’s total energy?
4) A soccer ball is rolling across the ground at a
constant velocity.
a. How can you do negative work on the
ball?
d. Right before the baseball hits the
ground, what velocity will the baseball
reach?
b. How can you do positive work on the
ball?
2) If a baseball (0.145 kg) is dropped from a height
of 35 m, how much kinetic energy will it have
right before it hits the ground? How do you
know?
5) Allie wants to design a rollercoaster that has a
fast velocity coming out of its first drop. She is
asking if her coaster needs to have a steep drop
or a gentle slope to reach the velocity desired.
What do you say to Allie?
6) Dom (92 kg) goes skydiving from 1200 m above
the ground (Assume no air resistance!).
a. What is Dom’s PE before he dives?
8) A gymnast does a pull-up and lifts his mass of
75 kg up 0.65 m in 0.45 seconds.
a. What is the gymnast’s power for one
pull-up?
b. After Dom falls 320 m, what is his PE?
b. How could the gymnast increase his
power?
c. After Dom falls 320 m, what is his KE?
d. After Dom falls 320m, how fast
(velocity) is he going?
Machines
9) What do machines do? (Use the words FORCE,
DISTANCE, and WORK in your answer)
10) An engineer is designing a ramp that must have
a height of 1.8 m. If the engineer wants to
expend no more than 2200N of force up the
ramp to move a 430 kg object, how long does
the ramp need to be?
Power
7) Austin moves a crate across the floor 12 m
while he pushes it with a force of 250 N. If
Austin moves the crate across the floor in 8.5
seconds, how much power does he have?
11) A 3-stringed pulley apparatus is pulling up a 23
kg object resting on the ground. How much
force is needed to pull the object up off the
ground.