A sled and rider, gliding over horizontal, frictionless ice at 4.5 m/s, have a combined mass of 74 kg. The sled then slides over a rough spot in the ice, slowing down to 2.6 m/s. What impulse was delivered to the sled by the friction force from the rough spot?

J = 525.4 Kg. m/s

Explanation:

given,

mass of the sled, m = 74 Kg

initial speed of the sled, v = 4.5 m/s

final speed of the sled, u = 2.6 m/s

Impulse = ?

Impulse is equal to change in momentum.

J = initial momentum - final momentum

J = m (v - u)

final speed, u = - 2.6 m/s

J = 74 x (4.5 - (-2.6))

J = 74 x 7.1

J = 525.4 Kg. m/s

Hence, the impulse delivered by the sled is equal to 525.4 kg. m/s