forces and presure

Question 1

Contact force

Answer 1

A force that acts when an object is in contact with a surface, air, or water.

Question 2

Friction

Answer 2

Force resisting movement because of contact between surfaces.

Question 3

Air resistance

Answer 3

The force of an object moving through air causing it to slow down.

Question 4

Gravity

Answer 4

A non-contact force acts between two masses.

Question 5

Non-contact force

Answer 5

A magnetic, electrostatic, or gravitational force that acts between objects not in contact.

Question 6

Interaction pairs

Answer 6

When two objects interact there is a force on each one that is the same size but in opposing directions.

Question 7

Newtons

Answer 7

The unit of force, symbol N.

Question 8

Deforms

Answer 8

When an object changes shape.

Question 9

Compress

Answer 9

To squash an object into a small space.

Question 10

Tension

Answer 10

A stretching force.

Question 11

Weight

Answer 11

The force of the Earth on an object due to its mass.

Question 12

Mass

Answer 12

Amount of stuff a thing is made of.

Question 13

Balanced

Answer 13

Forces acting on object that are equal and in opposite directions.

Question 14

Unbalanced

Answer 14

Opposing forces on an object that are unequal.

Question 15

what is meant by forces always come in pairs

Answer 15

it means that no matter what forces always have an opotion but they may not always be equel for example thrust and frict

Question 16

Atmosphere

Answer 16

The layers of gases that surround the Earth. The important gases in the atmosphere are nitrogen, oxygen and carbon dioxide.

Question 17

Atmospheric pressure

Answer 17

The weight of air resting on the Earth’s surface.

Question 18

Fluid

Answer 18

A substance that can flow, such as a liquid or a gas

Question 19

Normal

Answer 19

Acting at an angle of 90° to a surface or boundary.

Question 20

Pascal

Answer 20

Unit of pressure. Pascal (Pa), eg normal atmospheric pressure is 1.01x105 Pa.

Question 21

Pressure

Answer 21

Force exerted over an area. The greater the pressure, the greater the force exerted over the same area.

Question 22

surface area

Answer 22

The total area of an object, for example the area of a skydiver’s body facing the air as they fall, or the area of a car tyre that touches the road.

Question 23

upthrust

Answer 23

Upwards force exerted by a liquid or gas on an object floating in it.

Question 24

Pressure in gases

Answer 24

Gas pressure (air pressure) is when the air molecules collide into each other. Lots of collisions make a high gas pressure because there is a big force over a small area.

Question 25

Pressure in liquids

Answer 25

Liquids are incompressible. This is because the particles are very close together and touching each other, so there is very little space between them. The water molecules are pushing on each other and on surfaces, and this liquid pressure acts in all directions.

Question 26

Pressure on solids

Answer 26

When you stand on any surface you exert a force on it because of your weight. Your weight is spread out over the area of your foot. You are exerting a pressure on the ground.

Question 27

Turning forces

Answer 27

Whenever you open a door you are using a turning force. A turning force acts in a certain distance from a pivot. The turning effect of a force is called a moment. The moment depends on the force being applied and how far it is from the pivot. Moment equals force multiplied by perpendicular distance from the pivot.

Question 28

force

Answer 28

a push pull or twist that explains the way things move

Question 29

mass and weight

Answer 29

Mass and weight are two different quantities. Mass is the amount of matter in an object and weight is the force experienced due to gravity. The unit of mass is kg and the unit of force is Newton. The unit of gravitational field strength ‘g’ is N/kg. Mass is always the same anywhere in the Universe but weight changes as ‘g’ changes.

Question 30

how do things float

Answer 30

Liquids pass on any pressure applied to them. It is liquid pressure that produces upthrust, the force that keeps things afloat. If you push a balloon into a bucket of water you can feel the water pushing back. Upthrust acts on any object that is floating, or is submerged in a liquid.

Question 31

what forces do magnets exert

Answer 31

magnetic forces without them touching

Question 32

what is rubbing a balloon and picking up pieces of paper an example of

Answer 32

of electro static force

Question 33

what is a field

Answer 33

the region around an object that experiences a force

Question 34

what is gravitational field

Answer 34

where things with mass experience gravitational force

Question 35

do forces get stronger or weaker the further away from the field

Answer 35

weaker