# A car rolling down a hill accelerates from rest to 22m/s in 40s. What is the average velocity of the car? What is the displacement of the car as it rolls down the hill?

##### 1 Answer

Jul 6, 2018

#### Answer:

#### Explanation:

The car is rolling down a hill so the acceleration is constant.

This is because acceleration due to gravity is constant, so the acceleration of the car on a given slope will be constant (assuming the slope of the hill is constant and ignoring friction).

equations we know:

#v_("average")=(Delta d)/ (Delta t)# #v_("average")= (v_1-v_0)/2# (where#a# is constant)#a_("average")=(Delta v)/ (Delta t) # #d=v_("average")*t# #d=v_0 t+1/2at^2# (where#a# is constant)#Delta v = (v_1-v_0) = 22-0 = 22ms^(-1)# #Delta t =40s#

we know that the car accelerates from