The average resisting force that must act on a $5 \,kg$ mass to reduce its speed from $65 \,cm/s$ to $15 \,cm/s$ in $0.2\,s$ is .......... $N$
The average resisting force that must act on a $5 \,kg$ mass to reduce its speed from $65 \,cm/s$ to $15 \,cm/s$ in $0.2\,s$ is .......... $N$
$12.5$
$25$
$50$
$100$
The average resisting force that must act on a $5 \,kg$ mass to reduce its speed from $65 \,cm/s$ to $15 \,cm/s$ in $0.2\,s$ is .......... $N$
$F = m\,\left( {\frac{{v - u}}{t}} \right) = \frac{{5(65 - 15) \times {{10}^{ - 2}}}}{{0.2}} = 12.5\,N$