Question

Express the kinetic energy in kJ when a bike of 80 kg is moving with a velocity of 72 km h-1.

A) 13 kJ

B) 20 kJ

C) 16 kJ

D) 17 kJ

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Answer 1

d 17 is the right answer because it can divide

Answer 2

GIVEN :- MASS(m) of bike = 80 kg.

velocity(v) = 72 km/h

first we have to convert velocity to m/s,

velocity(v)= 72×5/18= 20 m/s.

∴ Kinetic energy (K.E) = 1/2 × MASS × (VELOCITY)².

                                    = 1/2× (80) × (20)²

                                    = 16000 J

                                   = 16 KJ.

HENCE, REQUIRED KINETIC ENERGY = 16 KJ.

THUS, (C) 16 KJ IS THE CORRECT OPTION.