Unit 4: Forces and Motion (Chapters 5, 6 and 7)
Test Study Guide
______always cause change in speed, direction or both.
Car ______moving a car forward is one activity in which friction is helpful.
Friction occurs because of the ______of any object’s surface.
Because they are in ______, astronauts in space appear weightless.
The equation for Newton’s second law of motion: ______
When a moving bumper car collides with a bumper car at rest momentum is ______to the car at rest.
A ball thrown level to the ground moves downward because ______pulls the ball toward the ground.
Where would atmospheric pressure be greatest: At the ocean, in a mountain city, at the outer edge of the atmosphere or where an airplane cruises? ______.
Why would a 1 cm3 piece of balsa wood (a soft, porous wood) be more buoyant than a 1 cm3 piece of oak (a hard, dense wood)? ______
DEFINE THE FOLLOWING:
The Law of Conservation of Mass (Matter)
Newton’s first law of motion
Newton’s second law of motion
Newton’s third law of motion
Buoyant force
Inertia
Centripetal force
Terminal velocity
SHORT ANSWER/ESSAY
Imagine a golf ball that is hit straight down the fairway. After it hits the ground, it rolls a long way. Why doesn’t it continue to roll forever?
If a baseball is hit into an outfield in which the ground is very SMOOTH, would the ball likely roll farther than if it were hit onto a ROUGH outfield? What causes the difference?
What distinguishes the measurement of speed from that of velocity and acceleration?
How do you calculate speed? Acceleration?
What is a net force?
Are the forces on a kicked soccer ball balanced or unbalanced? How do you know?
What must you know in order to determine the gravitational force between two objects?
You are a passenger in a car that is moving rapidly down a straight road. As the driver makes a sharp left turn, you are pressed against the right side of the car. Explain why this happens. Which of Newton’s Laws are at work here?
If a force of 26 N is exerted on two balls, one with a mass of 0.52 kg and the other with a mass of 0.78 kg, which ball will have the greater acceleration? Explain your answer. (Think about the mass (how heavy) each of the two balls are. If you hit the two with equal amounts of force will the lighter(the one with the least mass) or heavier one (the one with the most mass) move fastest?)
A skier with a mass of 45 kg moves with a velocity of 10.0 m/s east. What is the skier’s momentum? Hint: p (momentum) = m x v
In a closed soda bottle, the force on the cap due to the carbonation of the soda is 16 N. If the area of the bottle cap is 8 cm2, what is the pressure on the cap? Hint: the total force / area
What force works against a swimmer’s being able to dive deeply after taking a deep breath? Explain.
A cubic foot of fresh water weighs about 62.4 lbs, while a cubic foot of salt water weighs about 64 lbs. The Dead Sea contains about nine times more salt than the oceans. Which liquid (fresh water, salt water or water from the Dead Sea) do you think exerts the greatest buoyant force? Why? Hint: The heavier (more dense) the water the more it pushes up on an object with its buoyant force.
Why does pressure increase with depth?
Pilots have to adjust the plane’s wing flaps throughout a flight. Explain the purpose of these adjustments.
Wood usually floats, but some types of wood are more buoyant than others. For example, a cubic meter of balsa wood is more buoyant than a cubic meter of oak. Explain why this is true.
Why does water pressure increase as the depth of the water increases?
A 0.151 kg baseball is pitched with a velocity of 43.1 m/s. Ignoring air resistance, what is the baseball’s momentum after being pitched? Show your work. Hint: p(momentum) = m x v
A hiker’s initial speed at the bottom of the hill is 1.8 m/s and 1.5 m/s when the hiker reaches the top. It took the hiker 180 s to climb the hill. Explain how to calculate the hiker’s acceleration, including whether it would be positive or negative. Hint: acceleration = beginning speed - ending speed / the time it took to travel that distance.
List three ways of reducing friction in everyday life. Then list three examples of friction being helpful in everyday life.
Discuss how the gravitational force of the Earth affects you. Also, describe how the gravitational force of the sun affects you as compared to how it affects the Earth.
A student has a weight of 420 N on Earth. Assume that the moon’s gravitational force is exactly 1/6 the gravitational force on Earth. What would be the student’s weight in newtons on the moon? Explain your calculations.
How do you think the amount of pressure your body exerts on the ground is affected by whether you are standing, sitting, or lying down? Explain.
You have been given two different fluids with unknown densities. How could you determine which fluid is more dense without mixing the two fluids together?
You are part of a team that is raising a sunken ship from deep underwater. Several members of the team suggest inflating large balloons inside its hull. Do you agree with them? Why or why not?
Make sure you are able to graph and analyze graphs relating to speed, motion, velocity, acceleration, etc.
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