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8parks11

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An inter city Express locomotive pulls 14 cars, each with a mass of 53,000 kg. What is the tension in the coupling between the thrid and fourth cars when the acceleration of the train is 0.26m/s.

ok so I am looking for T.

F=ma

53000(0.26) = T?

i don't think this is correct because they mentioned 3,4 cars

or was that just random?

I don't know at all.

Added:

a) What is the minimum time in which one can hoist a 1.00-kg rock height of 10.0m if the string used to pull the rock up has a breaking strength of 10.8 N? Assume the rock to be initially at rest.

b) If the string is replaced by one that is 50% stronger, by what percentage will the minimum time for the hoist be reduced.

alright a) i just used a= 2(x-xo)/t^2 and then i got 2(10)/t^2 = 10.8/1

so i got 10.8=20/t^2 and so t would be root 10.8 but the answer is 4.5s... why??

b) i need to get a) to solve this...

ok so I am looking for T.

F=ma

53000(0.26) = T?

i don't think this is correct because they mentioned 3,4 cars

or was that just random?

I don't know at all.

Added:

a) What is the minimum time in which one can hoist a 1.00-kg rock height of 10.0m if the string used to pull the rock up has a breaking strength of 10.8 N? Assume the rock to be initially at rest.

b) If the string is replaced by one that is 50% stronger, by what percentage will the minimum time for the hoist be reduced.

alright a) i just used a= 2(x-xo)/t^2 and then i got 2(10)/t^2 = 10.8/1

so i got 10.8=20/t^2 and so t would be root 10.8 but the answer is 4.5s... why??

b) i need to get a) to solve this...

Last edited: