Question

What impulse was delivered to the sled by the friction force from the rough spot?

Answer 1

Answer:

- 80 Ns

Explanation:

The complete statement is given as

A sled and rider, gliding over horizontal, friction less ice at 4.0 m/s, have a combined mass of 80 kg. The sled then slides over a rough spot in the ice, slowing down to 3.0 m/s. What impulse was delivered to the sled by the friction force from the rough spot?

$v_{i}$ = initial velocity of the sled = 4.0 m/s

$v_{f}$ = final velocity of the sled = 3.0 m/s

$m$ = combined mass of sled and rider = 80 kg

$I$ = Impulse delivered to sled

Using Impulse-change in momentum equation, Impulse delivered to sled is given as

$I = m (v_{f} - v_{i})\\I = (80) (3 - 4)\\I = - 80 Ns$