Work Work Work Work Work
100 free points for everyone because I couldn't come up with another question for this one.
Yay!
When a bow string is drawn by a force that does 40J of work on it, how much Kinetic Energy will the arrow have, ideally?
40J
What is the conceptual definition of Potential Energy and Kinetic Energy?
Potential - energy due to position. Kinetic - energy due to motion.
How much potential energy does a .5 kg egg have, when raised 15 meters above the ground?
75 J
THE Moon
Earth
How much work is done in pushing a TV set a horizontal distance of 2m with an average force of 40N?
W = Fd = (40N)(2m) = 80J
A 5kg mass is held 6m above the ground. Relative to the ground, it has a potential energy of __________
30 J
What is the relationship between work and energy?
'Energy is the ability to do work' if you're in middle school, but I prefer 'All change requires work be done, all work done requires energy.'
While swinging on a swing at a play ground, you have your greatest kinetic energy at what point in your swing?
At the very bottom
Phobos, Deimos
Mars
A 1000kg car and a 2000kg car are hoisted to the same height for concurrent oil changes. Compare work required to lift each car.
The car with twice the mass will require twice the force to lift, and therefore requires twice the work.
A powerlifter raises 150kg weight a height of 2.7m. What is its GPE?
4050 J
DAILY DOUBLE
How much power is expended if you lift a 50 N rock 10 meters in 2 seconds?
250 Watts
Triton, Nereid, Naiad, Proteus
Neptune
How much power is expended doing 180J of work in 1.5 minutes?
2 Watts
A powerlifter has lifted a weight above their head, and holds it still for 2 seconds for the judges to count the lift as complete. How much work do they do on the weight during these 2 seconds?
NONE - no displacement means no work
Imagine a pendulum swinging back and forth without friction. At what points in the swing does the pendulum have the greatest potential energy?
The endpoints of the swing
If Skelly the skater’s speed is doubled, then his kinetic energy is increased by
4x
Ganymede, Callisto, Io, Europa
Jupiter
Both a 50-kg sack is lifted 2 meters from the ground and a 25-kg sack is lifted 4 meters in the same time. Compare the power required to lift each.
(50)(2) = (25)(4) = 100J of work done, both in the same time, therefore equal powers
At a track meet, a high-jumper leaps with an initial vertical velocity of 2m/s. How high do they jump?
0.2 m
Imagine a pendulum swinging back and forth without friction. At what points in the swing does the pendulum have the greatest kinetic energy?
The midpoint of the swing
How much kinetic energy does a pitcher have to give to a 1.2kg baseball to send it speeding towards home plate with a velocity of 40m/s?
960 J
Miranda, Puck, Oberon, Titania
Uranus