P8 - Forces And Ballance✔️

Question 1

what is magnitude?

Answer 1

size of a quantity

Question 2

what are scalars?

Answer 2

physical quantities that have size/magnitude but no direction

Question 3

what are vectors?

Answer 3

physical quantities that have size/magnitude and direction

Question 4

examples of scalar quantities?

Answer 4

distance, volume, density, mass, time, energy

Question 5

example of vector quantities?

Answer 5

force, velocity, displacement and acceleration

Question 6

equation for speed?

Answer 6

speed = distance/time

Question 7

equation for velocity?

Answer 7

velocity = displacement/time

Question 8

equation for force?

Answer 8

force = mass x acceleration

Question 9

why is acceleration a vector quantity?

Answer 9

acceleration is a change in velocity therefore having direction and therefore a vector making it a vector quantity.

Question 10

what do arrows show?

Answer 10

the direction of the vector quantity and the length represents the magnitude of the vector quantity.

Question 11

what is force?

Answer 11

a force is a push or pull that acts on an object. Force is measured in Newtons(N)

Question 12

what are example of contact forces?

Answer 12

friction, air resistance ,stretching(tension)

Question 13

what are example of non-contact forces?

Answer 13

magnetic force , gravitational forces , electrostatic force

Question 14

Newtons third law states …?

Answer 14

when two objects interact with each other they exert equal and opposite forces on each other. Example, if a person pushes a wall with a force of 50N the wall exerts and equal and opposite force back of 50N

Question 15

Newtons first law states ….?

Answer 15

in order to make an object move from rest the forces must be unequal.

Question 16

what is friction?

Answer 16

friction is the force exerted by a surface against an object when it moves across it.

Question 17

equation for calculating the size of a moment

Answer 17

moment(Nm) = Force(N) x distance(m)

Question 18

what is a moment?

Answer 18

a moment is a turning force, the turning effect of a force is called the moment of the force.

Question 19

what are pulley and gears?

Answer 19

pulleys and gears are both simple machines commonly used to transmit rotational forces whilst also increasing or decreasing this rotation force(turning effect)

Question 20

what is Centre of mass?

Answer 20

the mass of an object may be considered to act at a single point referred to as the objects ‘Centre of mass’.

Question 21

what is resultant force?

Answer 21

is the force that is produced in a certain direction due to a combination of forces if the resultant force is zero the object will remain stationary if the resultant force is not zero the object will accelerate in the direction of the resultant force.

Question 22

Newtons first law of motion states ….?

Answer 22

If the resultant force acting on a stationary object is zero then the object will remain stationary if the resultant force acting on a moving object is zero then object will continue moving in the same direction at the same speed.

Question 23

What is displacment?

Answer 23

Displacement is the distance moved in a straight line, in a given direction, from the starting point

Question 24

What happens when a car moves forward?Explain in terms of friction and forces?

Answer 24

Driving force on a car is the force that makes it move - this force pushes the car forward because their is friction between the ground an the tyre of each drive wheel

Question 25

What are the resultant forces on a plane taking off?

Answer 25

The thrust force of its engine is greater than the force of air resistance(drag) on it - the resultant force on the plane is the difference between thrust and air resistance and is therefore greater than 0

Question 26

Why does a car stop when the breaks are pressed explain in terms of resultant forces?

Answer 26

When breaks are applied the braking force is greater than the force from the engine - the resultant force if the difference between the braking force and the engine force

Question 27

Example of a lever?

Answer 27

Crowbar is a lever that can be used t o raise one edge on a heavy object

Question 28

What is the load when using a lever?

Answer 28

The load is the weight of the object

Question 29

What is the effort when using a lever?

Answer 29

Effort is the force the person applies to the lever

Question 30

Why is using a crowbar to lift a heavier object an exmaple of a force multiplier?

Answer 30

Because the effort moves a much bigger load

Question 31

What does a low gear give?

Answer 31

Low gear = low speed and high turning effect

Question 32

What does a high gear give?

Answer 32

High gear = high speed and low turning effect

Question 33

What does it mean if a lever is used as a force multiplier?

Answer 33

It exerts a greater force than the force applied to the lever by the pivot

Question 34

What happens to a small gear wheel when a low gear is used?

Answer 34

-Small gear wheel driven by engine shaft used to turn a large wheel on the output shaft -turning effect of the output shaft is greater than the turning effect of the engine shaft

Question 35

What happens to a large gear wheel when a high gear is used?

Answer 35

-Large wheel driven by engine shaft used to turn small gear wheel -Turining effect of the output shaft is greater than the turning effect of the engine shaft

Question 36

What is the centre of a mass of an object?

Answer 36

The centre of mass of an object is the point at which its mass can be thought as being concentrated

Question 37

Principle of moments?

Answer 37

Sum of all clockwise moments about any point = sum of all the clockwise moments about that point

Question 38

Equation for principal of moments?

Answer 38

W1 D1 = W2 D2 W=weight D=distance

Question 39

What is the parallelogram of focres?

Answer 39

Is a scale diagram of two vector forces - and is ued to find the resultant forces of two fores

Question 40

What are the two conditions for and object to be in equalibrium?

Answer 40

-resultant forces of an obect are equal -forces aacting on the object have no overall turning effect

Question 41

What does it mean to resolve a force?

Answer 41

Means finding perpendicualr components that have a resultant force that is equal to the force

Question 42

Is a bigger or lower turnig force exerted on the wheels with a low gear?

Answer 42

Bigger turning effect is exerted on the wheels