Motion and Forces

What is Newton's first law of motion?

• An object at rest will move in the opposite direction

• An object at rest will stay at rest, and an object in motion will stay in motion with the same speed and in the same direction unless acted upon by an unbalanced force.

• An object in motion will change speed and direction constantly

• An object in motion will eventually come to a stop

According to Newton's second law of motion, what is the relationship between force, mass, and acceleration?

• F = ma

• F = am

• F = a/m

• F = m/a

What is the SI unit of force?

• joule (J)

• kilogram (kg)

• meter per second (m/s)

• newton (N)

Explain the difference between static friction and kinetic friction.

• Static friction occurs when an object is in motion, while kinetic friction occurs when an object is at rest.

• Static friction and kinetic friction are the same thing.

• Static friction only occurs on rough surfaces, while kinetic friction only occurs on smooth surfaces.

• Static friction occurs when an object is at rest, while kinetic friction occurs when an object is in motion.

What is the net force acting on an object in equilibrium?

• 100 m/s^2

• zero

• 10 N

• negative

How does an unbalanced force affect the motion of an object?

• It causes the object to decelerate in the direction of the force.

• It causes the object to move perpendicular to the direction of the force.

• It causes the object to accelerate in the direction of the force.

• It has no effect on the motion of the object.

What is the formula to calculate force?

• force = distance / time

• force = velocity x time

• force = weight x acceleration

• force = mass x acceleration

Give an example of a force that causes a change in an object's motion.

• Friction

• Gravity

• Inertia

• Acceleration

Explain the concept of inertia in relation to Newton's first law of motion.

• Inertia is the tendency of an object to attract other objects

• Inertia is the tendency of an object to speed up its motion

• Inertia is the tendency of an object to change its shape

• Inertia is the tendency of an object to resist changes in its motion.

How does Newton's third law of motion explain the motion of a rocket in space?

• The rocket moves because of the gravitational pull of the Earth

• The rocket moves because of the heat generated by the engines

• The rocket propels itself forward by expelling gas in the opposite direction, according to Newton's third law.

• The rocket moves due to the force of the vacuum in space