Rotational Kinetic Energy: A solid ball of mass 1.0 kg and radius 10 cm rolls with a forward speed of 10 m/s when it comes to a hill. There is enough friction on the hill to keep the ball from slipping as it rolls up.(a) How high vertically up the hill can the ball roll before coming to rest?(b) How high vertically could the ball go if the hill were totally frictionless?(c) How is it that the ball can go higher with friction than without friction?
What will be an ideal response?
(a) 7.1 m (b) 5.1 m (c) With friction, all the initial kinetic energy (translational and rotational) goes into potential energy. Without friction, only the translational kinetic energy goes into potential energy; the ball keeps spinning at the same rate as it goes up, even at the top.
You might also like to view...
Because of Mercury's lower gravity, ejecta from a meteorite covers much of its surface
a. True b. False Indicate whether the statement is true or false
Suppose that the energy difference between adjacent energy levels for an oscillator in an Einstein solid is ? = 0.005 eV. We would expect the average energy of this oscillator when it is in contact with a reservoir at room temperature to be
A. negligible.
B. smaller than 
kBT.
C. about equal to kBT.
D. about equal to kBT.
E. significantly larger than kBT.
F. One doesn’t have enough information to tell.
What evidence do we have that Jupiter must have a substantial solid core under the thick clouds?
A) Its magnetic field must be form by rotating molten iron, like our own. B) Occasional breaks in the clouds reveal a solid surface at times. C) Jupiter's disk is more oblate than it should be, suggesting it has a higher density. D) Jupiter's disk is less oblate than it should be, if it were only hydrogen and helium. E) The Io flux tube goes straight down to Jupiter's iron core.
How many planet Earths could fit inside the Sun?
A) 110 B) about a thousand C) a little over a million D) almost ten million E) close to a billion