A truck weighs twice as much as a car, and is moving at twice the speed of the car. Which statement is true about the

ack's kinetic energy (K) compared to that of the car?

a. All that can be said is that the truck has more K.

b. The truck has twice the K of the car.

C. The truck has 4 times the K of the car.

d. The truck has 8 times the K of the car.

Answer: d

Explanation:

mass of truck mt, kinetic energy of truck Ekt (Kt), Vt - speed of truck

mass of car ma, kinetic enregy of car Ekc (Kc), Vc-speed of car

mass of truck mt=2*mc

speed of truck Vt=2*Vc

Compare Kinetic energy of truck with kinetic energy of car using equation to calculatation;

Kinetic energy of car:

Kc = (mc*Vc²) / 2

Kinetic energy for truck:

Kt = (mt*Vt²) / 2

Kt = ((2*mc * (2*Vc) ²) / 2

Kt = (2*mc*4*Vc²) / 2

Kt=8*mc*Vc²/2

Compare Kinteic energy truck with Kinetic energy of car:

Kt/Kc

Kt/Kc = ((8*mc*Vc²) / 2) / ((mc*Vc²) / 2)

Kt/Kc=8