maths/physics question below, please answer

Question

Need help answering P2, i know the answer to part 1. Im unsure how I work out P2. 

 

A car of mass 1.5 tonnes is driving up a hill, the hill makes an angle of 10 degrees to the
horizontal, at a constant 30km/h.

 

P1- Neglecting any friction, what is the power required from
the engine to drive the car up the hill under these conditions?

P2 -If the car takes 20 seconds to climb the hill, how much energy will the journey consume? If
the car now doubles its speed and so ascends the hill in just 10 seconds, how much
energy will the journey have consumed?

Answer 1

First part of P2:

 

Multiply the power by the length of the time interval, and that gives the amount of energy consumed.  You already know the power from P1.

 

Second part of P2:

 

Since you doubled the speed, the power is now twice as much.  Multiply that higher power by the length of the new time interval to get energy consumed.  You should get the same number, because the time went down to half when you doubled the speed.