Question

An open train car, with a mass of 2210 kg, coasts along a horizontal track at the speed 2.01 m/s. The car passes under a loading chute and, as it does so, gravel falls vertically into it for 2.83 s at the rate of 495 kg/s. What is the car\'s speed after the loading is completed? Ignore rolling friction (as unrealistic as that may be).

Answer 1

I got 5.49 as final answer dont know y it is wrong

Answer 2

hi there, got any idea?@Vincent-Lyon.Fr

Answer 3

First, do you realise your answer is unrealistic?
Second, what law did you use to compute the final velocity?

Answer 4

conserv of p

Answer 5

its mass reduced 2.83 times 495

Answer 6

so mivi=mfvf

Answer 7

I need vf and know the others

Answer 8

Ok, this is the right law to use.
Now, either you have put the wrong quantities in it, or you have made a computing mistake.

What are your values for mi, vi, mf and vf?

Answer 9

Sorry, What are your values for mi, vi and mf?

Answer 10

mi=2210,vi=2.01,mf=809.15

Answer 11

?? how can the mass of the car be less after some gravel was ADDED to it?

Answer 12

sorry, my english is terrible, cuz I have chinese as my first lang

Answer 13

no problem :)) Neither is it for me.
The situation is gravel falls into the car.

Answer 14

ok i'll see what I got this time, thx

Answer 15

Do you have the new value of mf?

Answer 16

3620.75 is new mf

Answer 17

and 1.22 is the correct vf

Answer 18

Great! 笑

Answer 19

Final mass is 3610.85 kg
Final velocity is 1.23 m/s

Answer 20

why 85?