Question 15

Question

A 1583.3 kg car is traveling at 20.1 m/s when the driver takes his foot o? the gas pedal. It takes 5.8 s for the car to slow down to 20 m/s. How large is the net force slowing the car?

Answer 1

First, we need to find the car's accelerations.

 

Given:

m = 1583.3 kg

v₁ = 20.1 m/s

v₂ = 20 m/s

t = 5.8

 

We can find the car's accelerations a₁ and a₂ using the formula

 

a = v/t

 

a₁ = (20.1 m/s) / (5.8 s)

a₁ = 3.47 m/s²

 

a₂ = (20 m/s) / (5.8 s)

a₂ = 3.45 m/s²

 

Now we can find the net force using the formula

 

F = mΔa

F = m(a₂ - a₁)

F = 1583.3 kg ( 3.45 m/s²  -  3.47 m/s²)

F = 1583.3 kg (-0.02 m/s²)

F = -31.67 kg m/s²

 

The net force is 31.66 N acting in the opposite direction of the cars motion.