First Semester Review! Created by Educational Technology Network. www.edtechnetwork.com 2009

Vectors and Projectiles Δx, v and a Force Momentum and Impulse Vectors and Projectiles Misc. 10 20 30 40 50

Δx, v and a - 10 This is a position vs. time graph. Which line represents an object with the greatest magnitude of velocity?

Answer 1 – 10 A

Δx, v and a - 20 The following is a position vs. time graph. Which line corresponds to an object with the greatest change in position?

Answer 1 – 20 A

Δx, v and a - 30 Position (m) Time (s) Over what time interval is the object moving backward?

Answer 1 – 30 15 – 40 s

Δx, v and a - 40 The following is a velocity vs. time graph Which object has the smallest displacement during the time interval of the graph?

Answer 1 – 40 D

Δx, v and a - 50 What is the displacement between 20 and 40 seconds?

Answer 1 – 50 0 m

Force - 10 What is the acceleration of the following 1kg object? 8N 6N

Answer 2 – 10 2 m/s2

Force - 20 If a 10kg mass is pulled across the floor at a constant velocity of 5 m/s by a 20N force, what is the coefficient of Kinetic Friction?

Answer 2 – 20 0.2

Force - 30 A 20kg box accelerates across the floor. The machine pushing the box exerts a 500N force and the coefficient of kinetic friction is 0.35. What is the acceleration of the box?

Answer 2 – 30 21.6 m/s2

Force - 40 The maximum velocity a 1000kg car can make a 20m radius curve is 8 m/s before sliding out. What is the force of static friction between the tires and the road?

Answer 2 – 40 3200 N

Force - 50 An 80kg skydiver has reached terminal velocity in her fall. What is the Force of Drag from the air on the ski diver?

Answer 2 – 50 784N

Momentum and Impulse - 10 A soccer ball is kicked with a force of 30N and the foot applies this force to the ball for 0.4 seconds. What is the change in momentum of the ball?

Answer 3 – 10 12kgm/s

Momentum and Impulse - 20 A 0.4kg beach ball is sitting at rest in the sand when all of a sudden a breeze picks up and starts the ball rolling down the beach at 2m/s. What impulse did the wind apply to the ball?

Answer 3 – 20 0.8 kgm/s

Momentum and Impulse - 30 A 10 kg block moving at 10m/s collides head on with a 20kg block at rest. The two blocks stick together. What is the velocity of the blocks after the collision?

Answer 3 – 30 3.33m/s

Momentum and Impulse - 40 Two football players run toward each other to block each other. One football player is 90kg and runs at 5m/s. The other player is 80 kg. How fast does the 80 kg player need to run in order to cancel out the momentum of the heavier player and bring both of them to a stop?

Answer 3 – 40 5.63 m/s

Momentum and Impulse - 50 Two cars are in a head on collision. Car 1 has a mass of 1000kg and is going 20 miles per hour to the right. Car 2 has a mass of 1500kg and is going 13 miles per hour to the left. The cars bumpers lock during the collision. Which direction will the tangled mess of cars skid after the collision?

Answer 3 – 50 To the right.

Vectors and Projectiles - 10 Two vectors are perpendicular to each other. One has a magnitude of 5 units, the other has a magnitude of 8 units. What is the magnitude of the resultant vectors?

Answer 4 – 10 9.4 units

Vectors and Projectiles - 20 A soccer ball is kicked from the ground at 12m/s at 35 degrees from the horizontal. If the ball is in the air for 1.4 seconds, how far away from the kicker does the ball land?

Answer 4 – 20 13.8 m

Vectors and Projectiles - 30 A rock rolls horizontally off of a 40m high cliff. How long is the rock in the air?

Answer 4 – 30 2.86 seconds

Vectors and Projectiles - 40 A boat which travels through the water at 10m/s heads straight across a river. The current of the river is 8m/s. What angle is the boat deflected off of its straight line path?

Answer 4 – 40 38.7 degrees

Vectors and Projectiles - 50 A cannon ball is launched from a cannon which can launch at any angle. If the velocity of the cannonball leaving the barrel of the cannon is 30m/s, what is the maximum range of the cannon?

Answer 4 – 50 91.8 m

Misc. - 10 Convert 10 m/s to miles per hour.

Answer 5 – 10 22.4 mph

Misc. - 20 What physical conditions determine the coefficient of friction? (Not asking for an equation)

Answer 5 – 20 The interaction between the two surfaces sliding. In other words the type of materials interacting.

Misc. - 30 You are in an elevator standing on a scale when suddenly the elevator drops at an accelerating rate of 4.9m/s2. If the reading on the scale before the fall was 700N, what will the scale read during the fall?

Answer 5 – 30 350N

Misc. - 40 Sketch a velocity vs. time graph for a bouncy ball dropping from some height, and then bouncing back up to nearly the same height.

Misc. – 40 V t

Misc. - 50 Sketch a position vs. time graph for a bouncy ball dropping from some height, and then bouncing back up to nearly the same height.

Misc. – 50 y t