Question

Need help on number 7. We need to use kinematic formulas

Answer 1

Part (a)

The final speed of body can be expressed as,

`v=u-gt`

Substitute the known values,

`\begin{gathered} 58.8m/s=0m/s-(-9.8m/s^2)t \\ t=\frac{58.8\text{ m/s}}{9.8m/s^2} \\ =6.0\text{ s} \end{gathered}`

Thus, the time taken by body to acquire the final speed is 6.0 s.

Part (b)

The distance covered by the body can be given as,

`d=ut-(1)/(2)gt^2`

Substitute the known values,

`\begin{gathered} d=(0\text{ m/s)(6.0 s)-}(1)/(2)(-9.8m/s^2)(6.0s)^2 \\ =0\text{ m+}176.4\text{ m} \\ =176.4\text{ m} \end{gathered}`

Thus, the vertical distance covered by body is 176.4 m.