Question

Test your prediction through calculation for the situations of the clay bob and the bouncy ball. Assume each has a mass of 100 grams, and each has an initial velocity of 20 m/s straight at the door. Ignore the effects of gravity. Calculate the change in momentum of

Answer 1

The change in momentum of the clay bob would be 2000 kg·m/s, while the change in momentum of the bouncy ball would be -2000 kg·m/s.

Step-by-step explanation:

For the clay bob, the change in momentum can be calculated using the formula: change in momentum = final momentum - initial momentum. Since the clay bob sticks to the motionless clay, the final momentum will be the sum of their initial momenta. The initial momentum of the clay bob can be calculated by multiplying its mass (100 grams) with its initial velocity (20 m/s), and the initial momentum of the motionless clay is zero. Therefore, the change in momentum would be 100 grams * 20 m/s = 2000 kg·m/s.

For the bouncy ball, the change in momentum can also be calculated using the same formula. Since the bouncy ball bounces off the door, it will experience a change in direction and its final momentum will have the opposite sign of its initial momentum. The initial momentum of the bouncy ball can be calculated by multiplying its mass (100 grams) with its initial velocity (20 m/s), and the final momentum will be the negative of that. Therefore, the change in momentum would be -100 grams * 20 m/s = -2000 kg·m/s.

Answer 2

a) Δp = -2.0 kgm / s, b) Δp = -4 kg m / s

Step-by-step explanation:

In this exercise the change in moment of a ball is asked in two different cases

a) clay ball, in this case the ball sticks to the door and we have an inelastic collision where the final velocity of the ball is zero

Δp = p_f - p₀

Δp = 0 - m v₀

Δp = - 0.100 20

Δp = -2.0 kgm / s

b) in this case we have a bouncing ball, this is an elastic collision, as the gate is fixed it can be considered an object of infinite mass, therefore the final speed of the ball has the same modulus of the initial velocity, but address would count

v_f = - v₀

Δp = p_f -p₀

Δp = m v_f - m v₀

Δp = m (v_f -v₀)

Δp = 0.100 (-20 - 20)

Δp = -4 kg m / s