Question

A number of discs, each of momentum $Mkgm/s$ are striking a wall at the rate of $n$ discs per minute. The force associated with these discs, in newtons, would be

• A. $\frac{Mn}{60}$
• B. $60Mn$
• C. $\frac{M}{60n}$
• D. $\frac{n}{60M}$

Answer 1

The correct option is A $\frac{Mn}{60}$

The force is $F=\frac{\Delta P}{dt}$

$momentum=Mkg.m/s$

change in time=rate of dics striking wall

$\Delta t=\frac{1}{n/minute}=\frac{60}{n}$

$F=\frac{\Delta P}{dt}=\frac{M}{60/n}=\frac{Mn}{60}N$