Some physics questions? help?

Question

Does the length of the pendulum's arm or its mass affect the period of its swing? why?

a] the mass causes the period [speed of swing] to be shorter or longer because the GPE [gravitional potential energy] is changed with the mass

b] the length causes the pendulum to have a shorter or longer period because of air resistance

c] the mass causes the period to be shorter or longer because thhe KE [kinetic energy] is changed with the mass

d]The length causes the pendulum to have shorter or longer period because it takes longer to swing through one cycle.

When a pendulum is at the top of its swing, how do the kinetic energy and gravitational potential energy compare?

A. The KE is zero while the GPE is half its highest value.

B. The KE is zero while the GPE is at its greatest value.

C. The GPE is zero while the KE is half its highest value.

D. The GPE is zero while the KE is at its highest value.

Answer 1

B

Answer 2

First one is D

The second one is B

pi=3.14, g=9.8m/s^2

Proof: 1.  T=2(Pi)sqrt(L/g)

so according to the formula if the length is longer then time is longer if the length is shorter the time is less.

Second one.  at height at max there is only GPE no KE exists there.  all the KE is converted to GPE so GPE is at max KE is at 0