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1 vote
How much force does it take to accelerate a 20 kg scooter speed from 10 m/s to 20 m/s?

a. 1000 j
b. 3000 j
c. 4000 j
d. 100 j

User DuckQueen
by
5.8k points

1 Answer

4 votes

That depends on how fast you want the speed to change from 10 m/s to 20 m/s. This is just another way of saying "what you want the acceleration to be".

F = m A

Force = (mass) x (acceleration)

If you want the speed to change from 10 m/s to 20 m/s in 1 second, then

Force = (20 kg) x (10 m/s²) = 200 Newtons

If you can wait a whole day for the speed to change gradually, then

Force = (20 kg) x (10 m/s)/(86,400 sec) = 0.00231... Newton

-- 1000 Newtons will complete the change of speed in 0.2 second

-- 3000 Newtons will complete the change of speed in 0.067 second

-- 4000 Newtons will complete the change of speed in 0.05 second

-- 100 Newtons will complete the change of speed in 2 seconds

Even if you KNOW the required acceleration, none of the choices on the list can be the correct force, because ' j ' is not even a unit of force.

User Eitanlees
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5.1k points