Chapter 3.2, Problem 21R

To determine

To Find: The mass of the skateboard.

Answer to Problem 21R

The mass of the skateboard is $2\text{kg}$ .

Explanation of Solution

Given info:

Acceleration, $a=0.5\text{m}/{\text{s}}^{\text{2}}$

Force, $F=30\text{N}$ East

Mass, $m_2=58\text{kg}$

Formula used:

The second law of motion equation

  $\begin{array}{c}a=\frac{F_{net}}{m}\\ F_{net}=a\times m\end{array}$

Here,

• $m$ is the mass.
• $F_{net}$ is the net force.
• $a$ is the acceleration.

Calculation:

Substitute the given values in the above equation

  $\begin{array}{c}F=m\times a\\ 30=\left(58+x\right)\times 0.5\\ x=2\text{kg}\end{array}$

Conclusion:

Hence, the mass $m_1$ is $2\text{kg}$ .