Chapters 4 and 6 Review

Chapter 4

• What are the units of mass?• What is the difference between mass and

weight?• What is the difference between mass and

volume?• How much does one kg weigh (in Newtons)?

Chapter 4

• Define net force• Define equilibrium• If all the forces on an object add up to zero,

can we say that the object is not moving?

Chapter 4

• What is the effect of friction on a moving object?

• If no force is required to maintain motion, why do you have to keep pedaling to keep your bike moving?

Chapter 4

• How much does 4 kg of feathers weigh?• Is this more or less than 4 kg of steel?• Which has the greater volume?

Chapter 4

• Find the net force:• F1 = 20 N to the right

• F2 = 15 N to the left

• Find the net force:• F1 = 20 N to the right

• F2 = 15 N to the right

Chapter 4

• Physical Challenge: Demonstrate Newton’s first law. DO NOT BREAK ANY OF DR. MASON’S EQUIPMENT OR INJURE ANY OF DR. MASON’S STUDENTS. OTHER TEACHERS’ EQUIPMENT OR STUDENTS IS OKAY.

Chapter 4

• Physical Challenge: Same as before, demonstrate Newton’s first law. But you have to do something different. DO NOT BREAK ANY OF DR. MASON’S EQUIPMENT OR INJURE ANY OF DR. MASON’S STUDENTS. OTHER TEACHERS’ EQUIPMENT OR STUDENTS IS OKAY.

Chapter 4

• If and elephant is chasing you, its weight would be threatening. But if you zigzag, its weight is to your advantage. Explain.

Chapter 4

• What is the weight of 3 kg of dimes?• What is the mass of 26 N of fish?

Chapter 6

• If you jump from a canoe onto the dock, does the canoe move when you jump? Why or why not?

• Does a stick of dynamite contain force?

Chapter 6

• If the action force is the earth pulling down on the falling rock, what is the reaction force?

• If the reaction force is the rocket pushing the gas out of the thrusters, what is the reaction force?

• If the action force is the cannon pushing the cannonball out, what is the reaction force?

Chapter 6

• If you hit a wall with a force of 100 N, what is the force the wall exerts on you?

• Why does this interaction hurt you more than it hurts the wall?

Chapter 6

• If you walk along a floating log, why does it move backwards?

• Why is it easier to move across a carpeted floor than a smooth, polished floor?

Chapter 6

• If action = reaction, why isn’t the earth pulled into orbit around an orbiting satellite?

• If a bicycle and a truck collide, which vehicle experiences a greater impact force? Which undergoes a greater change in its motion?

Chapter 6

• You exert 200 N on a refrigerator to push it across the floor at constant speed. What is the frictional force acting on the fridge?

• Does the frictional force constitute the reaction force to your push?

Chapter 6

• A rope connects two spring scales. You and a friend pull on either end of the scales, trying to get different readings on them. Can this be done?

• A balloon floats in midair. A balloonist climbs upwards on a support cable. In which direction does the balloon move?

Chapter 6

• A weightlifter exerts a force to lift a barbell. Is his force greater than, equal to or less than the weight of the barbell?

• How do you know?