Topic 5 Forces

Question 1

Vectors quantities

Answer 1

Have magnitude and direction. Eg force, velocity, displacement, acceleration and momentum

Question 2

Scalar quantities

Answer 2

Only have magnitude and no direction. Eg speed, distance, mass, temperature and time

Question 3

Contact force

Answer 3

Two objects have to touch for a force to act. Eg friction, air resistance, tension of ropes, normal contact force

Question 4

Non-contact force

Answer 4

When the objects don’t need to be touching to act. Eg magnetic force, gravitational force and electrostatic force

Question 5

Newton’s third law

Answer 5

When two objects interact the force exerted is equal and opposite on the two objects

Question 6

Gravitational force

Answer 6

The force of attraction between masses. It makes all things fall to the ground. And gives everything weight

Question 7

Mass

Answer 7

The amount of stuff in an object. Not a force. Measured in kilograms

Question 8

Weight

Answer 8

The force acting on an object due to gravity. Weight is higher for objects that have higher masses. It is a force that is measured in Newton’s

Question 9

The relationship of mass and weight

Answer 9

They are directly proportional

Question 10

Free body diagrams

Answer 10

It describes the forces acting on an object the sizes of the arrows show the relative magnitude of the forces and the directions they are going

Question 11

Resultant force

Answer 11

The overall force on a point or object. So the result of two forces pushing against each other

Question 12

Word done to an object

Answer 12

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

Question 13

Scale drawing

Answer 13

They find resultant forces.

Question 14

Equilibrium

Answer 14

When forces are balanced

Question 15

Stretching, compressing and bending

Answer 15

When more than one force acts on an object.

Question 16

Elastically deformed

Answer 16

When a force is applied to something and it returns to its original shape and length

Question 17

Inelastically deformed

Answer 17

When a force is exerted on an object causing it stay in a certain position and length

Question 18

What is the relationship between extension to force

Answer 18

They are directly proportional

Question 19

What happens if you continue to extend the spring

Answer 19

Eventually extension will increase but force will not and it has reached maximum force

Question 20

Moment

Answer 20

The turning effect of a force. The longer the distance from the pivot and the more energy exerted means a higher moment

Question 21

Levers

Answer 21

Make it easier to do work. Since moment = force x distance if the moment stays the same and the distance increases the force must decrease

Question 22

Gears

Answer 22

Gears interlock and turn in the opposite direction. Transmit the rotational effect of the force. Different sized gears change the moment so larger gear will cause a bigger moment. Larger gears will turn slower

Question 23

Pressure

Answer 23

The force per unit area. The particles move around exert a force on the object

Question 24

Pressure in liquids

Answer 24

Depends on depth and density. The more dense a liquid is the more particles it has so will collide and have a higher pressure. As the depth increases the number of particles above increases so the pressure increases

Question 25

Upthrust of objects in fluid

Answer 25

High