gaurav661
Mass of the car, m = 1000kg Initial velocity (v1) = 20m/s Final velocity (v2) = 10m/s Initial kinetic energy = 1/2 mv12 = 1/2 x 1000 x (20)2 = 200,000J Final kinetic energy=1/2 mv22 = 1/2 x 1000 x (10)2 = 50,000 J Work done by the brakes = change in kinetic energy = (K.E) 2 - (K.E) 1 = 50,000 - 200,000 = - 150000J = - 150KJ (The negative sign shows that the force applied by the breaks is in the opposite direction to the direction of motion of the body)
Answers & Comments
Initial velocity (v1) = 20m/s
Final velocity (v2) = 10m/s
Initial kinetic energy = 1/2 mv12
= 1/2 x 1000 x (20)2
= 200,000J
Final kinetic energy=1/2 mv22
= 1/2 x 1000 x (10)2
= 50,000 J
Work done by the brakes = change in kinetic energy
= (K.E) 2 - (K.E) 1
= 50,000 - 200,000
= - 150000J
= - 150KJ
(The negative sign shows that the force applied by the breaks is in the opposite direction to the direction of motion of the body)
plz change the number by yourself
MARK AS BRAINLIST