Standard 3.2A

State Newton's 1st Law

• An object at rest tends to stay at rest and an object in motion tends to stay in motion at a constant velocity unless acted upon by a net force.

• An object in motion tends to stay in motion at a constant velocity unless acted upon by a net force.

• An object at rest tends to stay at rest and an object in motion tends to stay in motion at a constant velocity.

• An object at rest tends to stay at rest and an object in motion tends to stay in motion unless acted upon by a net force.

State Newton's 2nd Law. Check all statements which form the law.

• The acceleration of an object is directly proportional to the force acting on the object and is in the same direction as the force

• The acceleration of an object is directly proportional to the net force acting on the object and is in the same direction as the net force

• The acceleration of an object is proportional to the mass of the object.

• The acceleration of an object is inversely proportional to the mass of the object.

• The net force acting on an object is directly proportional to the mass of the object

State Newton's 3rd Law.

• For every action there is always an equal and opposite reaction

• Whenever one object exerts a force on a second object, the second object exerts a force on the first

• Whenever one object exerts a force on a second object, the second object exerts an equal force on the first

• Whenever one object exerts a force on a second object, the second object exerts an equal and opposite force on the first

State the Conservation of Momentum

• In the absence of an external net force, the total momentum of a system does not change.

• In the absence of an external net force, the total momentum of a closed system does not change.

• The total momentum of a closed system does not change.

• In the absence of an internal net force, the total momentum of a closed system does not change.

Explain in terms of conservation of momentum why a heavy cannon has a smaller recoil velocity than the cannon ball. Select all that apply

• Initial momentum of the system is zero

• Final momentum of the system is zero

• Cannon and cannon ball have equal but opposite momenta

• Mass of cannon is greater than the mass of the cannon ball

What is the key concept necessary to solving every problem involving collision, objects pushing off each other, firing projectiles, etc.

• Total initial momentum of all objects = total final momentum of all objects

• Total initial velocity of all objects = total final velocity of all objects

• Total initial force of all objects = total final force of all objects

• Total initial acceleration of all objects = total final acceleration of all objects

An apple falls from a tree. Which is larger, the force of gravity of the Earth on the apple, or the apple on the Earth? Why does the Earth appear not to move?

• Earth on Apple; because the force of the apple on the Earth is so small

• Apple on Earth; because we are standing on the Earth and move with it

• Same force; the mass of the Earth is so much greater than the mass of the apple

A semi-truck collides with a small car. On which vehicle is the force larger?

• Semi-truck

• Small car

• Same on each

A semi-truck collides with a small car. On which vehicle is the impulse larger?

• Semi-truck

• Small car

• Same on each

A semi-truck collides with a small car. On which vehicle is the change in momentum larger?

• Semi-truck

• Small car

• Same on each