Question

A 2000kg suv accelerates from rest at a rate of 3.00m/s^2. The total amount of force resisting its motion 1500N. How much force is applied to the suvs tires by the ground to make it accelerate? The SUV now drives at a constant 18.0m/s. The total amount of force resisting it's motion is 2500 N. Now how much force is applied to the SUV's tires by the ground?

Answer 1

As we know by Newton's law

`F_(net) = ma`

`F - F_f = ma`

`F = F_f + ma`

here we have

`F_f = 1500 N`

`a = 3.0 m/s^2`

`F = 1500 + (2000)(3.0)`

`F = 7500 N`

so tyre apply net force of 7500 N in forward direction

After some time the SUV is travelling with constant speed

now in this case acceleration is ZERO

so now we will have

`F_(net) = 0 = F - F_f`

`F = F_f`

`F = 2500 N`