Question

A kid is on a stationary sled, onsnowy ground withus= 0.105.It takes 71.2 N of force to setthe sled moving. How muchnormal force is acting?(Unit = N)

Answer 1

We are given the following configuration:

Where:

`\begin{gathered} N=\text{ normal force} \\ F_f=\text{ force of friction} \\ W=\text{ weight} \\ F=\text{ pulling force} \end{gathered}`

Since we are given the force to set the body in motion this means that the pulling force is equal to the friction force, therefore, we have:

`F=F_f`

The friction force is given by the following formula:

`F_f=\mu N`

Substituting we get:

`F=\mu N`

Now, we solve for the normal force by dividing both sides by the coefficient of friction:

`(F)/(\mu)=N`

Now, we plug in the values:

`(71.2N)/(0.105)=N`

Solving the operations:

`678.1N=N`

Therefore, the normal force is 678.1 Newtons.