Question

A vehicle of mass 15 quintal climbs up on a hill 200m high. It then move on a level road with speed of 30m/s.calculate the potential energy gained by it and its total mechanical energy,while running on the top of a hill

Answer 1

m = mass of truck = 15 quintal = 15 x 100 kg = 1500 kg

h = height gained by truck = 200 m

Potential energy gained by truck is given as

PE = mgh

PE = (1500) (9.8) (200)

PE = 2.94 x 10⁶ J

v = speed of the truck on level surface = 30 m/s

kinetic energy of the truck is given as

KE = (0.5) m v²

inserting the values

KE = (0.5) (1500) (30)²

KE = 6.75 x 10⁵ J

Total mechanical energy is given as

TE = PE + KE

TE = (2.94 x 10⁶) + (6.75 x 10⁵)

TE = 3.615 x 10⁶ J

Answer 2

Answer: mechanical energy =36150 and potential energy=29400

Explanation:

so, as we know potential energy is mgh=p (where p is potential energy)

and kinetic energy =1/2mv2 (mv square)

so , as given in the question m=15,h=200m,v=30m/s

and we know g=9.8

apply the given values in the equation mgh for finding out the value of potential energy

15*200*9.8=29400

apply the given values in 1/2mv2 (mv square) and get the value of kinetic energy

1/2*15*30*30=6750

then , mechanical energy=kinetic energy+potential energy

so as we know both the values , substitute

29400+6750=36150

and here you go .. the answer is 36150