A sled and rider have a total mass of 57.2 kg. They are on a snowy hill accelerating at 0.5g. The coefficient of kinetic friction between the sled and the snow is 0.20. What is the angle of the hill's slope measured upward from the horizontal? You may find a spreadsheet program helpful in answering this question.

Answer 1

Harry Potter decides to take Pottery 101 as an elective to satisfy his arts requirement at Hogwarts. He sets some clay
(m = 4.00 kg)
on the edge of a pottery wheel
(r = 0.730 m),
which is initially motionless. He then begins to rotate the wheel with a uniform acceleration, reaching a final angular speed of 2.800 rev/s in 2.80 s.
(a) What is the speed of the clay when the initial 2.80 s has passed?

m/s

(b) What is the centripetal acceleration of the clay initially and when the initial 2.80 s has passed? (Enter the magnitudes of your answers.)
ac,i = m/s^2
ac,f = m/s^2

(c) What is the magnitude of the constant tangential acceleration responsible for starting the clay in circular motion?

m/s^2