Chapter SH, Problem 4.14APP

To determine

To calculate: Mass of the car.

Answer to Problem 4.14APP

Mass of the car is $\underset{\_}{2\times {10}^3\text{ kg}}$ .

Explanation of Solution

Given:

Kinetic energy = $900\text{ kJ}$

Velocity = $\text{30 m/s}$

Formula used:

Kinetic energy is given by,

  $KE=\frac{1}{2}m{v}^2$

Where m is mass and v is velocity.

Calculation:

Mass is calculated as:

  $\begin{array}{l}KE=\frac{1}{2}m{v}^2\\ m=\frac{2KE}{v^2}\\ m=\frac{2\left(\text{900}\times {\text{10}}^3\text{ J}\right)}{{\left(\text{30 m/s}\right)}^2}\\ m=\frac{2\left(\text{900}\times {\text{10}}^3\text{ J}\right)}{{\text{900 m}}^2/{\text{s}}^{\text{2}}}\\ m=2\times {10}^3\text{ kg}\end{array}$

Conclusion:

Mass of the car is $\underset{\_}{2\times {10}^3\text{ kg}}$ .