A 1200 kg car is traveling 21.1 m/s. It collides with a stationary car of mass 1500 kg, and the two vehicles lock together. What is the speed of the combined cars immediately after the collision? A) 7.5 m/s

B) 16.5 m/s

C) 9.4 m/s

D) 11.8 m/s

C) 9.4 m/s

Explanation:

= Mass of moving car = 1200 kg

= Initial velocity of moving car = 21.1 m/s

= Mass of stationary car = 1500 kg

= Initial velocity of stationary car = 0

v = Velocity of the combined cars

As the momentum in the system is conserved we have

The velocity of the combined mass is 9.4 m/s.

it would be c. predictability

note: the given question is incomplete.

complete question is given below.

which is an example of kinetic energy?

a. the energy stored in ethanol  

b. a hockey puck sliding across the ice  

c. a compressed spring  

d. a ball sitting at the top of a ramp

solution: the kinetic energy is the energy posses by the virtue of the motion of the object.

in the given options, a, c and d are the example of potential energy because it is the energy posses by the virtue of the rest of the object. but option b has the kinetic energy as the object is in motion.

hence, a hockey puck sliding across the ice   is the apex example of kinetic energy.

so, the option (b) a hockey puck sliding across the ice   is the correct option.