Forces 1

Question 1

What is a scalar quantity?

Answer 1

Magnitude (size).

Question 2

What is a vector quantity?

Answer 2

Magnitude (size) and direction.

Question 3

How might vectors quantities be represented with arrows?

Answer 3

The arrow length shows magnitude.

The arrow points in the direction that the vector quantity is acting.

Question 4

What type of quantity are forces?

Answer 4

Vector.

Question 5

When does a force occur?

Answer 5

When two or more objects interact.

Question 6

What are contact forces?

Answer 6

Objects are actually touching.

Question 7

What are examples of contact forces?

Answer 7

Friction.
Air resistance/drag.
Tension.
Normal contact force.
Upthrust.

Question 8

What are non-contact forces?

Answer 8

The objects are not touching.

Question 9

What are examples of non-contact forces?

Answer 9

Gravitational force.
Electrostatic force.
Magnetic force.

Question 10

What is gravity?

Answer 10

The force of attraction between all masses.

Question 11

What is the gravity close to Earth due to?

Answer 11

The gravitational field around the planet.

Question 12

What is the meaning of physics?

Answer 12

Pain.

Question 13

What is weight?

Answer 13

The force acting on an object due to gravity.

Question 14

How will physics be useful in everyday life?

Answer 14

To pass your exams. And beyond that…

Pain.

Question 15

What does this symbol - ∝ - mean?

Answer 15

Two things are proportional.

Question 16

How can weight be measured?

Answer 16

Using a newtonmeter.

Question 17

What is resultant force?

Answer 17

If more than one forces are acting on an object, yet one of the forces is greater than the others, this force is seen as the only force acting on the object.

Question 18

What does a free body diagram show?

Answer 18

Different forces acting on an object.

Question 19

What do scale vector diagrams show?

Answer 19

The overall effect when more than one force acts on an object.

Question 20

What happens when a forces causes an object to move?

Answer 20

Work is done on that object, as it requires energy to move that object.

Question 21

What happens when work is done?

Answer 21

Energy transfers take place in the system.

For example, work is done to overcome friction, which causes energy to transfers into heat energy.

Question 22

What must happen for one to change the shape of an object?

Answer 22

More than one force must be applied.

Question 23

What shows that an object has been elastically deformed?

Answer 23

It returns to its original shape after forces have been removed.

Question 24

What shows that an object has been inelastically deformed?

Answer 24

It doesn’t return to its original shape after forces have been removed.

Question 25

What is the extension on an elastic object directly proportional to?

Answer 25

The applied force; the have a linear relationship and produce a straight line on a force-extension graph.

Question 26

What happens once the limit of proportionality has been exceeded?

Answer 26

Doubling the force will no longer exactly double the extension. The relationship becomes non-linear. A force-extension graph will stop becoming a straight line.

Question 27

What is the spring constant?

Answer 27

It indicates how easy it is to stretch or compress a string.

Question 28

What type of quantity is distance?

Answer 28

Scalar.

Question 29

What type of quantity is displacement?

Answer 29

Vector.

Question 30

What type of quantity is speed?

Answer 30

Scalar.

Question 31

What type of quantity is velocity?

Answer 31

Vector.

Question 32

What is velocity?

Answer 32

The speed of an object in a given direction.

Question 33

What happens if an object is travelling in a straight line?

Answer 33

It has a constant speed and a constant velocity.

Question 34

What happens if an object is moving in a circle?

Answer 34

It is constantly changing direction, and therefore velocity. | It is accelerating even though it is travelling at a constant speed.

Question 35

What is Newton's first law?

Answer 35

An object will remain in the same state of motion unless acted on by an external force.

Question 36

What happens if the resultant force acting on an object is zero?

Answer 36

It continues to move at the same speed (stationary, otherwise), and the same direction.

Question 37

What is inertia?

Answer 37

The tendency for objects to continue in the same state of motion.

Question 38

What can a distance-time graph be used to represent?

Answer 38

The motion of an object travelling in a straight line.

Question 39

How might one find the speed on a distance-time graph?

Answer 39

By working out the gradient.

Question 40

What will a distance-time graph look like if an object is accelerating?

Answer 40

A curve.