Forces

Question 1

What is a force?

Answer 1

Is a vector quantity-vector quantities have a magnitude and a direction.

Question 2

Contact forces

Answer 2

Friction
Air resistance
Tention
Normal contact force

Question 3

Non-contact

Answer 3

Magnetic
Gravity
Static electricity

Question 4

Equal and opposite forces

Answer 4

When two objects push or pull on each other, they exert equal and opposite forces on one another.

Question 5

Resultant force is 0

Answer 5

If the resultant force is 0, forces acting on the object are balanced. The object remains stationary or continues to move at the same speed and same direction as before.

Question 6

Resultant force not 0

Answer 6

The forces on the object are not balanced. The movement of the object depends on the size and direction of the resultant force.

Question 7

Mass

Answer 7

Number is fixed. It depends on the quantity of matter in it.

Question 8

Weight

Answer 8

Is the force of gravity on it. It’s measured in Newtons.

Formula: weight=mass*gravitational field strength

Question 9

Hooke’s law

Answer 9

The extension of an object is directly proportional to the force that is applied to it, as long as it’s limit of proportionality is not exceeded.

Question 10

Elastic object

Answer 10

If it returns to its original shape when the forces deforming it are removed.

Question 11

Vector quantities

Answer 11

• force
• velocity
• displacement
• acceleration
• momentoum

Question 12

Scalar quantities

Answer 12

Physical quantities that only have a magnitude and no direction.

Question 13

Scalar quantities :

Answer 13

• speed
• distance
• time

Question 14

Vectors

Answer 14

Represented by arrows. The length of the arrow shows magnitude and the direction of the arrow shows the direction of the quantity.

Question 15

Gravitational force

Answer 15

Is the force of attraction between masses.

Question 16

Work done

Answer 16

When a force moves an object trough a distance energy is transferred and work is done on the object.

Question 17

1 j=

Answer 17

1Nm (Newton meters)

Question 18

Equilibrium

Answer 18

If all forces acting on an object combine to give a resultant force 0, therefore, the forces are balanced.

Question 19

Limit of proportionality

Answer 19

There is a maximum force, when the extension is no longer proportional to force.

Question 20

The energy in the elastic potential energy store (graph)

Answer 20

Is equal to the area under a force-extension graph.

Question 21

Friction

Answer 21

Is a force between two surfaces, which opposes the motion and may result in heating.

Question 22

Air resistance

Answer 22

Is a form of friction.

Question 23

Formula for Extention

Answer 23

F(force) = k (constant) * e (extension)

Question 24

Forces can change…

Answer 24

the shape of an object or change its state of rest or its motion.

Question 25

Newton’s Third Law

Answer 25

When two objects push or pull on each other, they exert equal and opposite forces on one another.

Question 26

Newton’s First Law of motion

Answer 26

If the resultant force on an object is zero, the object:

• remains stationary if it was in equilibrium
• continues to move at the same speed and in the same direction

Question 27

The resultant force is as a single…

Answer 27

force that has the same effect as all the forces acting on an object.

Question 28

Newton’s Second Law

Answer 28

If the resultant force is not 0, the object will accelerate in the direction of the resultant force.

Question 29

Resultant force formula

Answer 29

N = mass (kg) x acceleration (m/s2)