Work
A truck carrying a 36 kg crate accelerates uniformly from rest to 79 km/hr in 18.6 s. Calculate the work done on the crate by the truck (in J).
Hint: Hint:
This is an example of the work energy theorem. Just find the KE gain of the crate. This has to equal the work put into it.
Don't forget to convert the velocity to m/s.
Solution:
Initial kinetic energy = 0.
Final kinetic energy = work put into the acceleration of the crate:
W = (1/2) m v2
= (1/2) (36 kg) · (79 km/hr)2
= 8668.05555555555 J
Hint: Hint:
This is an example of the work energy theorem. Just find the KE gain of the crate. This has to equal the work put into it.
Don't forget to convert the velocity to m/s.
Solution:
Initial kinetic energy = 0.
Final kinetic energy = work put into the acceleration of the crate:
W = (1/2) m v2
= (1/2) (36 kg) · (79 km/hr)2
= 8668.05555555555 J