Helppp on this physics question?

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S135

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You need to find the mass first so.

Ek= 1/2 mv^2

100J= 1/2 m (5)^2

100J/25= 1/2m

4=1/2m
8 Kg= m............So know just use Ek formula again:

Ek= 1/2mv^2

=1/2(8kg)(10m/s)^2
=90J
 
An object travelling at 5 m/s is known to have a kinetic energy of 100 J. What would its kinetic energy be when it is travelling at 10 m/s?
 
You need the equation KE = 1/2mv²
They give you v = 5 and KE = 100. Solve for m:
100 = 1/2*m*5²
12.5m = 100
m = 8
Now for the second part, you have v = 10. Mass does not change, so we still have m=8 from the first part. Solve for KE:
KE = 1/2*8*10²
KE = 400
So, its kinetic energy would be 400J. In general, if the velocity is doubled, then the kinetic energy increases by a factor of 4. Hope this helps!
 
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