Question

a truck weighting 1500kgf changes it's speEd from 36km/h to 54km/h in 2 minutes.
calculate (1) the work done by the engine. (2) the power( g is equal to 10 m/s​

Answer 1

Given:-

• Mass of truck ,m = 1500kg

• Initial velocity ,u = 36km/h

• Final velocity , v = 54km/h

• Time taken ,t = 2min

• Acceleration due to gravity,g = 10m/s²

To Find:-

1. Work done ,W.
2. Power , P

Solution:-

Converting the unit here

Initial velocity = 36×5/18 = 10m/s

Final velocity = 54×5/18 = 15m/s

Time taken = 2×60 = 120s

[1]

As we know that work done is defined as the product of mass and acceleration.

→ W = mg

Substitute the value we get

→ W = 1500×10

→ W = 15000J.

∴ The work done by the truck is 15000 Joules.

[2]

Now, Calculating the power

→ Power = Work done/time

Substitute the value we get

→ P = W/t

→ P = 15000/120

→ P = 125 w

∴ The power is 125 watt.