a 2.0 x 103 kg truck is driving down a hill at 105 km/hr when a dog runs out on the road 94m in front of it

Question

A 2.0 x 103 kg truck is driving down the road at 105 km/hr when a dog runs out on the road 94m in

front of it. The driver’s reaction time is 0.35 seconds before hitting the brakes. The coefficient of

kinetic friction between the time and mud is 0.8. Will the truck hit the dog? (Hint: find the distance

the truck goes before the brakes are put on, then find the distance the truck takes to stop)

Answer 1

So the stopping distance will be v₀t_rxn +( -v₀²/2a)

a for this problem is F_f/m = mgμ/m = gμ (note that this acceleration is in the negative direction)

Don't forget to express v₀ in m/s