UPDATED QUESTIONS AND ANSWERS
◉The builders of the pyramids used a long ramp to lift 20000 kg
blocks. If a block rose 1 m in height while traveling 20 m along the
ramp's surface, how much uphill force was needed to push it up the
ramp at a constant velocity? . Answer: 9800
(SEE NOTES FOR EXPLANATION)
◉A ball is thrown straight upward. It rises in the air and then falls
back to the earth. Neglect friction. . Answer: On the way up, kinetic
energy is converted into potential energy.
(Skater example)
◉What influences or effects causes the Earth to rotate steadily,
turning once every approximately 24 hours? . Answer: The Earth is
essentially free of external torques, so it rotates at constant angular
velocity.
◉Can two riders ever sit on the same side of the seesaw and still
balance the seesaw? . Answer: No
, ◉I am pushing a file cabinet to your right along a level floor. In
which direction does the floor's frictional force on the file cabinet
act? . Answer: Toward your left
◉When you hold a beverage can upright between two fingers, one
on the right and one on the left, are you exerting any frictional forces
on the can, if so, in which direction are these frictional forces? .
Answer: Upward
◉Which type of friction waste ordered energy (work) as disordered
energy (thermal energy) . Answer: Sliding friction but not static
friction
◉If your toaster is labeled as using 1000 watts. How much energy
does it consume in 1 hour? . Answer: 1000 watts = 100 T/S
(Explanation in slides and pics)
◉Your momentum is equal to... . Answer: Your mass times your
velocity p = mv
◉After cleaning the bar on the high jump, you land softly on a giant
mattress. Landing on a mattress is more comfortable than landing
on a sand heap of equal size because? . Answer: The force the