Question

A 1 kg mass has a kinetic energy of 1 Joule when its speed isA. 0.45 m/sB. 1.4 m/sC. 1 m/sD. 4.4 m/s

Answer 1

Kinetic energy = 1/2 x mass x velocity^2

Where:

Kinetic energy = 1 J

mass = 1 kg

Isolate v (speed)

KE = 1/2 m v^2

√(2KE/m) = v

v = √(2KE/m)

Replacing with the values given:

v = √(2*1/1)

v= √2 = 1.4 m/s

Answer: 1.4 m/s (B)