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?

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

Substitute the values

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

when jerome paddle in flowing river towards east the net speed of jerome will increase

so the net speed of jerome will be given as

now the speed of paul will be same as it is given as he is running on the ground

so

so here we can say since the speed of jerome is more so he will win the race

now as we know the distance so the time difference is given as

so jerome will reach first and the time difference will be 203.55 s or 3.4 min