Question

The speed of a 1000-kg car whose KE is 450 kJ is

Answer 1

KE= 1/2mv^2

(1/2)(1000kg)(17m/s)^2 =144.5kJ, where kJ is 1000 Joules, or 1000 kg*m^2/s^2

Answer 2

Given - Mass and kinetic energy

Find - Speed

Solution - The velocity or speed of the car is 30 metres/second

The kinetic energy is given by the formula = 1/2*mass*velocity².

Keep the values in the formula to find the velocity.

450*1000 = 1/2*1000*velocity²

Cancelling 1000 as it is present on both sides of equation.

Velocity = ✓450*2

Performing multiplication to find velocity.

Velocity = ✓900

Finding the square root to find the velocity.

Velocity = 30 metre/second

Thus, the velocity or speed of the car is 30 metres/second