A Smart Car, which has a mass of 1000 kg, is going 20 m/s. When it hits the barrier, it stops with a time of 0.5 seconds. What is the acceleration of the car?

The acceleration = -40 ms⁻²

Explanation:

We know that,

a = (v₂ -  v₁) / t

  = 0 - 20 / 0.5

  = -20 / 0.5

  = -40 ms⁻²

Thus, the acceleration = -40 ms⁻²

okay i have so many questions. but the big one here is: um wt..f is this mess? ?

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.