What force is necessary to accelerate a 3000 lbs railway electric car at the rate of 1.25 ft/sec2, if the force required to overcome the frictional resistance is 400 lbs.

If the net force on a cart is tripled then what will be the net acceleration?

1. There will be no change in acceleration

2. The net acceleration will be tripled 

3. The net acceleration will be double

4. The next acceleration will be one-third

Which of the friction force is greater on an object?

1. Sliding friction

2. Static friction

What is the amount of force required to maintain the motion of a body at a constant speed?