Chapter 4 Test Review

Displacement, velocity, acceleration and force are vectors. Vectors are represented by arrows, the length being the magnitude, the direction as indicated

The unit of force is the Newton (N) a newton is a kg(m/s2) mass acceleration Force is a push or pull, such as pushing on a wall, or gravity pulling you down (weight)

SF = ma mass = 10 kg What is the force of gravity pulling down on this ball? (10 extra credit points to whoever shouts out the correct answer first…) What is the net force if there is 10 N of air resistance opposing the fall (10 points to somebody else…)

Newton’s Third Law of Motion For every action force, there is an equal and opposite reaction force… 10 N 10 N

If there is no acceleration (constant velocity), there is no net force. Forces left = forces right. Forces up = forces down. 80 m/s

A baseball player hits a baseball. What forces are acting on the baseball, after the hit? friction ? (we’ll ignore air resistance) b. the force of the hit ? c. the normal ? d. gravity ? e. tension ?

Friction is f = mN 100 Kg pulled with a force of 10 N at a constant speed of 5 m/s What if the force of friction? What is the normal force? What is the coefficient of friction?

Label all of the forces Fp (T) N Fpy f Fpx mg

Box sliding down an inclined plane… label the forces Which force pushes the box down the slope? N f F┴ mg FII

Label the forces… Fp (T) Fpy N Fpx f F┴ mg FII

hangs from three ropes. What is the tension in the middle rope? A ball with a mass of 20 Kg hangs from three ropes. What is the tension in the middle rope? T2 T1 = 30 N T3 = 50 N q1 = 85° q3 = 42° mg = 20 Kg (9.81 m/s2) = 196.2 N sin 85° (30N) + sin 42° (50N) + T2 = 196.2N T2 = 196.2N - sin 85° (30N) - sin 42° (50N) T2 = 132.8N