1) Which Point has the most potential energy?
A) C
B) B
C) A
D) D
• A IS THE CORRECT ANSWER
Point C has the most potential energy because the height is the highest. The equation for PE is PE=mgy, with y being the height.
2) What is the amount of work done from a person lifting a 50
kg boulder up 5 meters.• A) 2250 J
• B) 2500 J
• C) 2450 J
• D) None of the above
AnSwEr!~!
• The answer is C. Since Work is force times the change in x, you must first solve for force. Force is calculated with mass times acceleration, being 50 kg x 9.8m/s2
• This equals 490 Newtons of force multiplied by the 5 meters it went, equalling 2450 J.
3) What is energy in motion?
A) Kinetic Energy
B) Potential Energy
C) Thermal Energy
D) Nuclear Energy
ANSWER!
• The answer is A because kinetic energy is energy in motion.
4) If the kinetic energy is 1000J, and the mass is 125 kg, what is
the velocity?
A) 5 m/s
B) 4 m/s
C) 3 m/s
D) 8 m/s
ANSWER
• The answer if 4 m/s. The kinetic energy (1000 J) is equal to ½ mv2. The mass is 125 kg so when you multiply the 1000 J times 2 to cancel the ½ and divide by the 125 kg you have 16=v2. V is then equal to 4 m/s.
5) As an object falls, what happens to its potential energy?
A) It increases
B) It decreases
C) It stays the same
ANSWER
• When an object falls, the potential energy is converted into kinetic, making the potential decrease.
6) As an object continues to fall, what happens to the TME (Total
Mechanical Energy)?A) It increases
B) It decreases
C) It stays the same
ANSWER
• The TME stays the same because of the law of conservation of energy.
7) The higher you go up, the less potential energy you get.
A) True
B) False
ANSWER
• The answer is false, the higher you go up, the more potential you have because the PE is calculated with PE=mgy, with y being the height. It height increases, so does PE!
8) If work stays the same, and time doubles, what happens to
power?A) It doubles
B) It gets halved
C) It stays the same
ANSWER
• The power gets cut in half because power and time are inversely related in the equation P=w/t.
9) What is the equation for work?
A) W=C x T
B) W= F x X
C) W= P/T
ANSWER
• The answer is B, W= F x X .
10) Alex picks up a 50 kg box and throws it straight up 10 m.
What is the work done?A) 4,900 J
B) He’s god
C) 490 J
D) 5,100 J
ANSWER
• The answer is A. The Force is 50 kg times 9.8, which is the acceleration. The force is multiplied by the 10 meters it moved giving you 4900 J.
