T5 - Forces

Question 1

Feature of scalar quantities?

Answer 1

only have magnitude

Question 2

Feature of vector quantities?

Answer 2

have magnitude and direction

Question 3

What does length of arrow show in forces?

Answer 3

magnitude

Question 4

what does direction of arrow show?

Answer 4

direction of vector quantity

Question 5

what is a force?

Answer 5

a push or pull that acts on an object due to the interaction with another object.

Question 6

What is a contact force?

Answer 6

when the objects are physically touching

Question 7

What is a non-contact force?

Answer 7

when the objects are physically separated.

Question 8

equation for weight?

Answer 8

weight(N)= mass(kg)× gravitationalfieldstrength (N/kg)

Question 9

What is weight?

Answer 9

the force acting on an object due to gravity

Question 10

Correlation between mass and weight of an object?

Answer 10

directly proportional

Question 11

What is weight measured with?

Answer 11

Newtonmeter

Question 12

What is the centre of mass?

Answer 12

The weight of an object at a single point

Question 13

What is a resultant force?

Answer 13

a single force that has the same effect as all the original forces acting together

Question 14

Equation for work done?

Answer 14

Work done(J) = Force(N) x Distance(m)

Question 15

What is elastic deformation?

Answer 15

when elastic material returns to original shape when force is removed

Question 16

What must happen to change shape of an object?

Answer 16

more than 1 force applied

Question 17

What is inelastic deformation?

Answer 17

when inelastic materials do not return to original shape when force is removed

Question 18

equation for force in elasticity?

Answer 18

force(N)= spring constant(N/m) × extension or compression(M)

Question 19

What is the moment of a force?

Answer 19

turning effect of a force

Question 20

equation for moment?

Answer 20

moment(Nm) = force(N) × distance(m)

Question 21

What distance should be used for measuring moments?

Answer 21

perpendicular distance

Question 22

What is a fluid?

Answer 22

a gas or liquid

Question 23

What does the pressure in fluids to any surface?

Answer 23

a force at right angles to any surface.

Question 24

Equation for pressure?

Answer 24

pressure(Pa) = right angle force of surface(N) / area of that surface(M^2)

Question 25

What happens to density of atmosphere when altitude increases?

Answer 25

density decreases

Question 26

Equation for column of liquid?

Answer 26

pressure(Pa) = height of the column(m) × density of the liquid(Kg/m^3) × gravitational field strength(N/kg)

Question 27

Why does pressure of liquid increases with depth?

Answer 27

greater weight of liquid acting downwards

Question 28

Why does pressure increase with density?

Answer 28

greater weight of liquid acting downwards

Question 29

Why does the bottom of an object experience more pressure than the top in a liquid?

Answer 29

bottom is at a greater depth

Question 30

What must happen for an object to float?

Answer 30

upthrust equals weight of object

Question 31

What must happen for an object to sink?

Answer 31

upthrust less than weight of object

Question 32

equation for speed?

Answer 32

speed = distance / time

Question 33

What is the normal walking speed?

Answer 33

1.5 m/s

Question 34

what is the running speed?

Answer 34

3 m/s

Question 35

what is the cycling speed?

Answer 35

6 m/s

Question 36

Factors that affect walking, running and cycling speed? x4

Answer 36

-age -terrain -fitness -distance

Question 37

What is speed of sound in air?

Answer 37

330 m/s

Question 38

What happens to velocity when an object is moving around a circle in a constant speed?

Answer 38

velocity changes

Question 39

equations for acceleration? x2

Answer 39

acceleration(m/s^2) = change in velocity(m/s) / time taken(s) final velocity^2 − initial velocity^2 = 2 × acceleration × distance

Question 40

How to find distance traveled in a velocity time graph?

Answer 40

area under graph

Question 41

what is the acceleration of a free falling object under gravity near earths surface?

Answer 41

9.8 m/s^2

Question 42

what eventually happens to an object falling through a fluid?

Answer 42

-resltant force goes to 0 -reaches terminal velocity

Question 43

What is newtons first law of motion for a stationary object?

Answer 43

If the resultant force acting on an stationary object is 0, then the object remains stationary

Question 44

What is newtons first law of motion for a moving object?

Answer 44

If the resultant force acting on a moving object is 0, then the object will continue moving in the same direction at the same speed

Question 45

What is newtons second law of motion?

Answer 45

The acceleration of an object is proportional to the resultant force acting on the object, and inversely proportional to the mass of the object.

Question 46

Equation for resultant force?

Answer 46

resultant force(N) = mass(kg) × acceleration(m/s^2)

Question 47

How fast does a car travel on main road?

Answer 47

13 m/s

Question 48

How fast does a car travel on motor way?

Answer 48

30 m/s

Question 49

what is the acceleration required for a car on main road to go onto motor way?

Answer 49

2 m/s^2

Question 50

what is the force required for a car on main road to go onto motor way?

Answer 50

2000N

Question 51

What is inertia?

Answer 51

The tendency of objects to stay still or keep same motion

Question 52

What is inertial mass?

Answer 52

a measure of how difficult it is to change the velocity of an object

Question 53

What is newtons third law of motion?

Answer 53

Whenever two objects interact, the forces they exert on each other are equal and opposite.

Question 54

What is the stopping distance of a vehicle?

Answer 54

sum of thinking distance and braking distance

Question 55

Typical value range for reaction time?

Answer 55

0.2s-0.9s

Question 56

Factors that affect thinking distance? x4

Answer 56

-tiredness -drugs -alcohol -distractions

Question 57

Factors that affect braking distance? x3

Answer 57

-wet and icy conditions -worn tires -worn brakes

Question 58

what does large deceleration in vehicle lead to? x2

Answer 58

-brakes overheating -loss of control

Question 59

Equation for momentum?

Answer 59

momentum(kg m/s) = mass(kg) × velocity(m/s)

Question 60

What is conservation of momentum?

Answer 60

In a closed system, the total momentum before an event is equal to total momentum after the event.

Question 61

safety features for momentum? x5

Answer 61

-seat belt -air bag -bike helmet -crash mat -cushioned surface in playground