Question

force and motion

1. force is:

a) the amount of matter in an object
b) the speed of an object
c) a push or pull on an object
d) the distance an object travels

1. which force slows down or stops the motion of an object?

a) friction
b) magnetism
c) gravity
d) air resistance

1. what happens when you push a heavy box with more force?

a) the box becomes lighter
b) the box moves faster
c) the box becomes smaller
d) the box stops moving

1. which force keeps objects on the ground?

a) friction
b) magnetism
c) gravity
d) buoyancy

Explanation:

Question 1

To determine the correct definition of force, we analyze each option:

• Option a: The amount of matter in an object is mass, not force. Eliminate a.
• Option b: The speed of an object is related to motion, not the definition of force. Eliminate b.
• Option c: By definition, force is a push or pull on an object. This matches the scientific definition.
• Option d: The distance an object travels is displacement or distance, not force. Eliminate d.

To find the force that slows down or stops motion, we analyze each option:

• Option a: Friction is a force that opposes motion, causing objects to slow down or stop. This fits.
• Option b: Magnetism is a force related to magnetic fields, not directly slowing motion. Eliminate b.
• Option c: Gravity is a force of attraction, mainly affecting weight and free - fall, not slowing motion in the general sense of opposing motion. Eliminate c.
• Option d: Air resistance is a type of friction (fluid friction), but the general term for a force that slows or stops motion is friction. Option a is more general.

When pushing a heavy box, we consider the effect of force on motion (Newton's second law, \(F = ma\), where \(F\) is force, \(m\) is mass, and \(a\) is acceleration).

• Option a: The mass of the box (which determines its "heaviness") doesn't change when we apply force. Eliminate a.
• Option b: According to \(F = ma\), if we apply more force (\(F\) increases) and the mass (\(m\)) of the box remains constant, the acceleration (\(a\)) increases. So the box will move faster. This is correct.
• Option c: The size of the box doesn't change with the application of force. Eliminate c.
• Option d: Applying more force should make the box move, not stop. Eliminate d.

Answer:

c. A push or pull on an object

Question 2