Question

four rods of same material but with different radii and lenghths are used to connect two reserviors of heat with the same temp. difference. which one will conduct more heat?

a] r=1cm , l=1m

b] r=1cm , l=2m

c] r=1cm,l=1/2m

d] r=1/2cm , l=1/2m

Answer 1

Mass of the ball, m = 150 g = 0.15 kg

Initial speed of the ball, u = -12 m/s

Final speed of the bal after being hit, v = 20 m/s

Impulse = change in momentum = final momentum initial momentum

= Impulse = 0.15 × 20 0.15 × (-12) = 4.8 Ns