Ch 4. Physical Science. Review.
An apple weighs 1 N. The magnitude of net force on the apple when it is in free-fall is?
1 N
An object is pulled northward with a force of 10 N and southward with a force of 15 N. The magnitude of the net force on the object is?
5 N
Which has zero acceleration? An object...
At rest, and moving constantly.
Which has the greater mass? A.) King-size pillow B.) Automobile Battery C.) Both about the same
B.) Automobile battery
Force Pair
The action and reaction pair of forces that occur in an interaction.
A hockey puck is set in motion across a frozen pond. If ice friction and air resistance are neglected, the force required to keep the puck sliding at constant velocity is?
0 N
What is the relationship between force and mass when acceleration is produced?
A given force exerted on a small mass produces a large acceleration, while the same force exerted on a large mass produces a small acceleration.
When can forces cancel each other?
Forces cancel only when they act on the same object.
If the action is A acting on B, what is the reaction?
If the action is A on B, the reaction is B on A.
In what specific way do forces occur in every interaction?
In every interaction, forces always occur in pairs.
Compared with a 1-kg block of solid iron, a 2-kg block of solid iron has twice as much?
Inertia, Volume and Mass
Specifically, what force pushes a system across the ground?
It is the outside reaction force by the ground that pushes the system.
A force is a vector quantity because it has both?
Magnitude and Direction
A kilogram is a measure of an object's?
Mass
An object maintains its state of motion because it has?
Mass
Interaction
Mutual action between objects where each object exerts an equal and opposite force on the other.
What laws of physics got humans to the Moon?
Nevertheless, and quite interestingly, it was primarily Newton's laws that got us to the Moon.
A car has a mass of 1000 kg and accelerates at 2 m/s/s. What is the magnitude of the force exerted on the car?
2000 N
On the surface of Jupiter, where the acceleration due to gravity is about 3 times that of Earth, a 100-kg rock would have a weight of about?
3000 N.
A 10-N falling object encounters 4 N of air resistance. The magnitude of the net force on the object is?
6 N
If the mass of an object does not change, a constant net force on the object produces constant?
Acceleration
Compare the relative strengths and directions of action and reaction forces.
Action and reaction forces are equal in strength and opposite in direction.
When you stand at rest on a pair of bathroom scales, the readings on the scales will always?
Add to equal your weight.
An object is propelled along a straight-line path by a force. If the net force were doubled, its acceleration would?
Double
A sheet of paper can be withdrawn from under a container of milk without toppling it if the paper is jerked quickly. This best demonstrates that?
The milk carton has inertia
Compared with the mass of a certain object on Earth, the mass of the same object on the Moon is?
The same
What must a team do to win in a tug-of-war?
The team to win is not the team to exert the greatest force on the rope, but the greatest force against the ground.
Newton's Third Law
Whenever one object exerts a force on a second object, the second object exerts an equal and opposite force on the first. Or put another way, "To every action there is always an opposed equal reaction."
The force required to maintain an object at a constant velocity in free space is equal to?
Zero
Whenever the net force of an object is zero, its acceleration is?
Zero