Question

A city planner is working on the redesign of a hilly portion of a city. An important consideration is how steep the roads can be so that even low-powered cars can get up the hills without slowing down. It is given that a particular small car, with a mass of 1110 kg, can accelerate on a level road from rest to 19 m/s (68.4 km/h) in 15.0 s. Using this data, calculate the maximum steepness of a hill.


The maximum net accelerating force the , ignoring friction, can give is found by

Force= mass*maxacceleration

On the hill, this force has to overcome the downward force of gravity of the car. The force of gravity is related to the component of weight DOWN the hill.

forceabove= forcegravity
forceabove=m*g*sinTheta

calculate Theta from this

Answer 1

Set acceleration to 0, since you want to keep the same speed.