Question

Six dogs are pulling a sled which is sliding across the snow at a constant speed. The force of friction between the sled and snow is 180N. How much force does one dog pull?

Answer 1

F = 30 N/dog

Step-by-step explanation:

Given

Ff = 180 N

n = 6 dogs

We apply Newton's 2nd Law as follows

∑F = m*a since v is constant, a = 0

then

∑F = 0 (→+) ⇒ nF - Ff = 0

where F is the force exerted by one dog

6*F - 180 N = 0 ⇒ F = (180 N)/6 dogs

⇒ F = 30 N/dog

Answer 2

`F = 30\,N`

Step-by-step explanation:

According to the 2nd Newton's Law, a system moving with net force equalized to zero is at rest or moving at constant speed. The total pulling force has the same magnitude than friction force but opposite direction. Let assume that each dog is pulling the sled with the same force, then:

`F = (180\,N)/(6)`

`F = 30\,N`