chrisyabantony14
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#1
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#1
The rollercoaster car is raised a vertical distance of 35 m to point A by a motor
in 45 seconds.
The mass of the rollercoaster is 600 kg.
The motor has a power rating of 8 000 W
(a) calculate the percentage efficiency of the motor
Gravitational field strength= 9.8N/Kg



help me please I'm stock
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Muttley79
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#2
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#2
(Original post by chrisyabantony14)
The rollercoaster car is raised a vertical distance of 35 m to point A by a motor
in 45 seconds.
The mass of the rollercoaster is 600 kg.
The motor has a power rating of 8 000 W
(a) calculate the percentage efficiency of the motor
Gravitational field strength= 9.8N/Kg



help me please I'm stock
Hint - what work has been done by the motor to raise the car 35m?
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chrisyabantony14
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#3
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#3
(Original post by Muttley79)
Hint - what work has been done by the motor to raise the car 35m?
please explain me I'm just in year 10 in want to learn that please
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Muttley79
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#4
(Original post by chrisyabantony14)
please explain me I'm just in year 10 in want to learn that please
Why are you doing questions on topics you have not been taught?

Work done = Force x distance moved in the direction of the force
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thekidwhogames
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#5
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#5
600kg = 600x9.8=5880N
power = energy/time = 5880x35 / 45.

Now calculate the %.
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chrisyabantony14
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#6
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#6
(Original post by thekidwhogames)
600kg = 600x9.8=5880N
power = energy/time = 5880x35 / 45.

Now calculate the %.
thanks
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chrisyabantony14
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#7
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#7
(Original post by thekidwhogames)
600kg = 600x9.8=5880N
power = energy/time = 5880x35 / 45.

Now calculate the %.
I still don't understand
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thekidwhogames
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#8
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#8
(Original post by chrisyabantony14)
I still don't understand
You know power = energy / time
You know the mass and therefore the force. So the energy (or work done) = force x distance therefore the power will be fd/t.
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revisionphysics
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#9
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#9
(Original post by chrisyabantony14)
The rollercoaster car is raised a vertical distance of 35 m to point A by a motor
in 45 seconds.
The mass of the rollercoaster is 600 kg.
The motor has a power rating of 8 000 W
(a) calculate the percentage efficiency of the motor
Gravitational field strength= 9.8N/Kg



help me please I'm stock

So efficeiency= Puseful/Pin *100
So we have Power in = 8000W

All we need is Power that is useful in this case the power that the thingy uses to move up.

To work that out we can use

P=Energy/time

We have the time = 45

We now need the energy.

The energy = work done (same thing) can be worked out from the equation

Gpe E = mgh

So M =600
g=9.81
H =35

Plug that in you get and then try to work out the answer.
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chrisyabantony14
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#10
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#10
(Original post by revisionphysics)
So efficeiency= Puseful/Pin *100
So we have Power in = 8000W

All we need is Power that is useful in this case the power that the thingy uses to move up.

To work that out we can use

P=Energy/time

We have the time = 45

We now need the energy.

The energy = work done (same thing) can be worked out from the equation

Gpe E = mgh

So M =600
g=9.81
H =35

Plug that in you get and then try to work out the answer.
thanks all of you I get it now thanks do much
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chrisyabantony14
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#11
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#11
(Original post by revisionphysics)
So efficeiency= Puseful/Pin *100
So we have Power in = 8000W

All we need is Power that is useful in this case the power that the thingy uses to move up.

To work that out we can use

P=Energy/time

We have the time = 45

We now need the energy.

The energy = work done (same thing) can be worked out from the equation

Gpe E = mgh

So M =600
g=9.81
H =35

Plug that in you get and then try to work out the answer.
but can I get the percentage efficiency of the motor?
I got everything but
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