Force ⚡

Question 1

What is force?

Answer 1

Force is anything that causes a change in an object’s motion.

Question 2

Force is something that can cause a change in which 3 factors?

Answer 2

• speed
• direction
• shape

Question 3

What are vector quantities and what are some examples?

Answer 3

Vector quantities have both a magnitude and a direction. Examples include velocity, displacement, acceleration, force, and momentum.

Question 4

What are scalar quantities and what are some examples?

Answer 4

Scalar quantities only have a magnitude but no direction. Examples include distance, mass, temperature, time, etc.

Question 5

What is velocity?

Answer 5

Velocity is the speed in a particular direction.

Question 6

What is displacement?

Answer 6

Displacement is the distance between an object’s initial position and its final position.

Question 7

What is momentum?

Answer 7

Momentum can be defined as “mass in motion.” All objects have mass; so if an object is moving, then it has momentum

Question 8

Why is distance a scalar quantity?

Answer 8

Because if we walk a distance of 3km we do not have any idea of the direction we only know the distance therefore distance is a scalar quantity.

Question 9

What is Newton’s first law of motion?

Answer 9

An object at rest remains at rest, and an object in motion remains in motion at a constant speed unless acted upon by an unbalanced force.

Question 10

What is Newton’s second law of motion?

Answer 10

The size or the force depends on the mass of the object and the acceleration of the object. The law also states that the direction of the motion is the direction of the force acting on it.

Question 11

What is Newton’s third law of motion?

Answer 11

This law tells us that every force comes in pairs meaning a force always has another force acting on it.

Question 12

Note: when objects are balanced, the object will either be at rest or moving at a constant speed and when the forces acting on an object are unbalanced, then the object will either speed up or slow down.

Answer 12

Understood? 🤔

Question 13

What is an example of a field force?

Answer 13

Gravity is a force that can exert a force on another object without being in direct contact with it (these forces are known as field forces.

Question 14

What is a ‘field’ in science?

Answer 14

A field is a space where an object may experience a force.

Question 15

What are 4 of the main types of forces?

Answer 15

• Frictional forces
• Electrostatic forces
• Magnetic forces
• Gravitational forces

Question 16

Define friction

Answer 16

Friction is a contact force that uses motion to generate energy.

Question 17

What is static friction?

Answer 17

Static friction is the force of friction on an object that is not moving in other words it is the opposing force when you apply another force.

Question 18

What is kinetic friction?

Answer 18

Kinetic friction occurs when the force reaches the maximum static friction and starts moving.

Question 19

Initially, you need to apply a large force for an object to move but once the object is in motion you need to apply a less force why?

Answer 19

Because the kinetic friction is less than the limiting friction when an object is in motion.

Question 20

How is kinetic friction a constant force?

Answer 20

Kinetic energy is a constant force meaning once an object is in motion the kinetic friction does not depend on the force but the surfaces in contact.

Question 21

What are the 2 disadvantages of friction?

Answer 21

• It can produce heat energy causing objects to wear
• Objects continuously rubbing against each other will eventually break down due to the heat.

Question 22

What is a constant force?

Answer 22

If the force object stays the same and doesn’t change over time.

Question 23

What is Static electricity?

Answer 23

Static electricity is the result of a contrast between negative and positive charges in an object.

Question 24

Note: Sometimes atoms gain electrons, making it negatively charged and sometimes atoms gain protons making it positively charged. It is the movement of electrons and protons that creates a spark (e.g. lightning)

Answer 24

Understood🤔

Question 25

What happens when you rub a balloon against a wool sweater?

Answer 25

The atoms in the wool lose electrons, making it positively charged and the atoms in the balloon lose protons making it negatively charged. Therefore the positively charged sweater will pull on the negatively charged balloon making the balloon stick to the sweater.

Question 26

Note: An electrostatic force is an example of a field force because objects do not need to be in contact to expert a force on another object (although they can be in contact).

Answer 26

Understood? 🤔

Question 27

In electrostatic forces:
- _____________
- _____________
-______________

Answer 27

• charged object attract uncharged objects
• objects that have the same charge repel each other
• objects with different charges attract each other

Question 28

What are magnetic forces?

Answer 28

Magnetic forces is a field force that acts on certain objects called magnets.

Question 29

Note: Magnets attract objects made of
- ___________
- ___________
- ___________
- ___________

Answer 29

• iron
• steel
• cobalt
• nickel

Question 30

Note: In magnets like poles repel each other, unlike poles attract each other, and a magnet with one poll cannot exist.

Answer 30

Understood? 🤔

Question 31

Properties of a magnetic field includes:

Answer 31

• The path of the magnetic force starts on the north pole and ends in the south pole
• Near the poles the magnetic field lines come closer together creating force force in those regions.
• Magnetic field lines can never intersect each other.

Question 32

How do compasses know the direction of north and south.

Answer 32

Earth behaves like a giant magnet. Like a magnet, it is surrounded by a magnetic field. This magnetic force attracts all magnets (e.g. compass). This is how compasses know the direction of north and south.

Question 33

Gravity is the weakest force. True or false?

Answer 33

True, Gravity is the weakest force.

Question 34

What is gravity?

Answer 34

Gravity is the force caused when there is the gravitational force of the Earth pulling on an object.