Question

A 2000-kg railway freight car coasts at 4.4 m/s underneath a grain terminal, which dumps grain directly down into the freight car. If the speed of the loaded freight car must not go below 3.0 m/s, what is the maximum mass of grain that it can accept?

Answer 1

Answer:

933. 3kg

Explanation:

We are given that

Mass,m=2000 kg

Initial speed,u=4.4 m/s

We have to find the maximum mass of grain if the speed of loaded freight car must not go below 3.0 m/s.

Final speed,v=3 m/s

By conservation of momentum

Initial momentum=Final momentum

$mu=m'v$

Substitute the values

$2000\times 4.4=m'(3)$

$m'=\frac{2000\times 4.4}{3}$

$m'=2.93\times 10^3 kg$

Mass of freight loaded car=2933.3 kg

Mass of grains=2933.3-2000=933.3 kg

Hence, the maximum  mass of grains that it can accept=933.3 kg