Question

A. What is the Kinetic Frictional Force on the Sled?(40 N)

b. If the weight of the sled is 200 N, what is the co-efficient of Kinetic Friction (uk) between
the sled and snow?(0.20)
c. If 30 kg of wood is placed in the sled, what pulling force is needed to move the
sled at constant velocity?(98.8 N)​

Answer 1

Given:

Pulling force= 40N

Mass of sled= 200N

Weight of wood= 30kg= 30 X 9.8N = 294N

Solution:

a) Since the sled is moving with constant velocity

⇒ net acceleration on sled= 0

⇒ net force on sled= 0

⇒ Pulling force= frictional force

⇒ Frictional force= 40N

b) Frictional force= μ N = μ mg

or 40 = μ X 200

or μ= 0.2

c) If 30 kg of wood is placed in the sled, new normal reaction= 294 + 200N

Pulling force required= frictional force

= μ N'

= 0.2 X 494

= 98.8N