hi guys!
may i know why will a car increase in speed even though its forward driving force is constant?
thank you!!
In common terms, for a start, there's an initial amount of resistance force, usually friction and air resistance acting on your car, for example 1000N.
Your constant forward force, is let's say, 5000N, and is used to drive the car, overcoming the friction, allowing you to have excess force to increase your speed.
However, as friction increases with speed [Air resistance largely], later your car will reach a limit speed point, where all the force is later used to overcome the resistance whilst maintaining your speed.
Of course if you start to look deeper into the situation, factors such as momentum and inertia, it helps to give a clearer view.
Assuming the forward driving force applied is constant throughout, the car will speed up until the forward driving force is equal to friction (assuming no air resistance, car traveling in straight line etc.). This is the max speed which the car can reach with that amount of driving force.
At that instant, the driving force applied is used to balance out the frictional force the car experiences.
Some things to note: At that max speed (constant), the car is moving at a constant speed and there is no net force on the car. Friction on the car increases as the speed of the car increases.