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Mechanics

Calculate the force required (in Newtons) to accelerate a train of mass 500 tonnes from rest to a velocity of 30km/hr in 20 minutes.Give your answer to the nearest whole number.

Need help please...
You need to show your attempt at the working first. This isn't a homework service.

This is a daft model without any resistance forces but you just need to combine v=u+atv=u+at with F=maF=ma.
Original post by Sarmi
Calculate the force required (in Newtons) to accelerate a train of mass 500 tonnes from rest to a velocity of 30km/hr in 20 minutes.Give your answer to the nearest whole number.

Need help please...

Firstly, I like to work in standard units, so I will convert :smile:

30kph = 8 1/3 m/s
20 minutes = 1200s
500 tonnes=500000kg

So, we know a=(v-u)/t. So a=(8 1/3 - 0)/1200. a=0.00694444... m/s^2

We know f = m a

F = 500000 x 0.00694444...
F = 3,472.2222 N
F = 3,472 N
S
U= 0
V= 30,000
A=?
T= 20*60

Sub into v=u + at
Then sub a into F=(mass of truck in kg) * accelearation
Reply 4
Thank You
Reply 5
Original post by CharlieBoardman
Firstly, I like to work in standard units, so I will convert :smile:

30kph = 8 1/3 m/s
20 minutes = 1200s
500 tonnes=500000kg

So, we know a=(v-u)/t. So a=(8 1/3 - 0)/1200. a=0.00694444... m/s^2

We know f = m a

F = 500000 x 0.00694444...
F = 3,472.2222 N
F = 3,472 N


You're not supposed to post full solutions mate...

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