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BMAT Physics

Hi there!!

Is there anyone who could help me out with this question... I just don't get it .. :frown:

27 A car of mass 800kg moves up an incline of 1 in 20 (1 in 20 means for every 20m along the road
the car gains 1m in height) at a constant speed of 20m/s. The frictional force opposing motion is
500N.
How much work has been done by the engine after the car has moved 50m?

A 20kJ
B 25kJ
C 27kJ
D 45kJ
E 65kJ
F 160kJ



THanks all!!
Original post by Roqia
Hi there!!

Is there anyone who could help me out with this question... I just don't get it .. :frown:

27 A car of mass 800kg moves up an incline of 1 in 20 (1 in 20 means for every 20m along the road
the car gains 1m in height) at a constant speed of 20m/s. The frictional force opposing motion is
500N.
How much work has been done by the engine after the car has moved 50m?

A 20kJ
B 25kJ
C 27kJ
D 45kJ
E 65kJ
F 160kJ



THanks all!!



Welcome to TSR physics.
The work done by the engine is made up of two parts
1) the work to increase its potential energy going up the slope. (Find the height it rises from the gradient given)
2) The work done against the friction over that 50m.

Does that help?

When you post here you need to tell us exactly what you are stuck on. What bits you understand and can do (and have done!), and what you can't. This makes it easier for us to help you.
Reply 2
Original post by Stonebridge
Welcome to TSR physics.
The work done by the engine is made up of two parts
1) the work to increase its potential energy going up the slope. (Find the height it rises from the gradient given)
2) The work done against the friction over that 50m.

Does that help?

When you post here you need to tell us exactly what you are stuck on. What bits you understand and can do (and have done!), and what you can't. This makes it easier for us to help you.


Hi Stonebridge!

Thanks for trying to helping me out!! I really appreciate it :smile:

That is what I was thinking as well : I initially thought this Kinetic Energie = potential energy + resistance energy + energy of the engine , but I couldn't solve it ...

Maybe you can try to help me again. Your explanation IS very good, but not really clear.

Thanks !
Original post by Roqia
Hi Stonebridge!

Thanks for trying to helping me out!! I really appreciate it :smile:

That is what I was thinking as well : I initially thought this Kinetic Energie = potential energy + resistance energy + energy of the engine , but I couldn't solve it ...

Maybe you can try to help me again. Your explanation IS very good, but not really clear.

Thanks !



I've told you how to do it.
And the two amounts together in 1) and 2)
What don't you understand.
Do you know how to calculate potential energy?
Do you know how to calculate work done by a force moving through a distance?
You need to tell us what you don't understand.
It's not enough just to say you need help.
BMAT physics is pretty hard considering its meant to be gcse standard.

Bloody hell

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