A child is playing with a toy car, and it accelerates to the south from 1.2 m/s to 6.3 m/s. If the toy car's
acceleration is 2.75 m/s2, what is the amount of time
that the child takes to accelerate the car?

1.86s  

Explanation:

Given parameters:

Initial velocity  = 1.2m/s

Final velocity  = 6.3m/s

Acceleration  = 2.75m/s²  

Unknown:

Time it takes for the child to accelerate the car  = ?

Solution:

Acceleration is the rate of change of velocity with time.

   a   =  

a is the acceleration

v is the final velocity

u is the initial velocity

t is the time taken

               2.75  =  

                 5.1 = 2.75t

                 t  = 1.86s  

measure their densities same density, same sub

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.