# physics

posted by
**mimi**
.

1. A ball moving horizontally clears a net 2 meters high. What maximum speed can it have if it is to fall within 5 meters of the net?

2.A pulley system lifts a load of 800 Newtons, 20 centimeters while the rope pulling it moves 100 cm.

a. How much force must be applied to lift the load?

b. What is the mechanical efficiency of this system if the actual applied force is 200 N?

3. The braking distance for a car traveling 20 mph is 20 m (slippery). What is the braking distance if you are traveling 60 mph?

4. A 1 kg cart starting from rest slides down an incline starting from 1.5 meters high. (The incline is 2.5 m long.) Assuming a frictionless incline,

a. What is the speed (value of the velocity) at that point?

b. what is the kinetic energy of the cart when it has slide down to a point 1 meter high?