# Question #5fc94

Oct 13, 2017

The frictional force is 9.8 N.

#### Explanation:

I will assume 1) this mass is on a horizontal surface and 2) the 70 N force is applied horizontally.

The formula for the frictional force, ${F}_{f}$, is

${F}_{f} = \mu \cdot N$

where $\mu$ is the coefficient of friction and N is Normal force. Normal force means the force pressing the object to the surface it is sliding on. In this case, it is the weight of the mass, so $N = m \cdot g$.

${F}_{f} = 0.02 \cdot 50 k g \cdot 9.8 \frac{m}{s} ^ 2 = 9.8 N$

The net force will be
$70 N - 9.8 N = 60.2 N$
The friction will not be large enough to prevent the mass from sliding, so the mass will accelerate.

I hope this helps,
Steve