At one particular moment, a 19.0 kg toboggan is moving over a horizontal surface of snow at 4.40 m/s. After 8.50 s have elapsed, the toboggan stops. Use a momentum approach to find the magnitude of the average friction force (in N) acting on the toboggan while it was moving.

Answer: 9.8Newton

Explanation:

Initial velocity = 4.40 m/s.

Final velocity = 0 m/s

Mass of toboggan = 19.0kg

Time taken = 8.50 seconds

Frictional force, F. F = (Change in momentum of moving toboggan / Time taken)

Since, change in momentum = Mass (final velocity - initial velocity)

Change in momentum = 19.0 x (0 - 4.40)

= 19.0 x (-4.40)

= - 83.6 kgm/s

Then, put - 83.6 kgm/s in the equation of force when frictional Force = (Change in momentum / Time taken)

F. F = ( - 83.6 kgm/s / 8.50 seconds)

F. F = 9.8Newton (note that the negative sign does not reflect on the magnitude of force)

Thus, the magnitude of the average friction force is 9.8Newton