**Check list answers:- from syllabus, similar to book**

**Section 1: Forces and motion**

**a) Units**

Students will be assessed on their ability to:

**1.1**use the following units:

kilogram (kg), --------------------------------mass m

metre (m), -------------------------------------length l

metre/second (m/s), -----------------------velocity v

metre/second2 (m/s2), -------------------acceleration a

newton (N), -----------------------------------Force F

second (s), ------------------------------------time t

newton per kilogram (N/kg), ------------gravitational field strength g

**kilogram metre/second (kg m/s)**. --momentum p

**b)**

**Movement and position**

**1.2**plot and interpret distance–time graphs

a) straight line with increased gradient means greater speed/velocity,

b) straight line with shallow gradient means slower speed/velocity,

c) Blue curved line on right, slope is changing, slope is increasing, therefore it is ACCELERATING

d) Horizontal lines means the distance stays the same, but time is moving on, therefore its stationary

**constant speed**, NOT ACCELERATINGb) straight line with shallow gradient means slower speed/velocity,

**constant speed**, NOT ACCELERATINGc) Blue curved line on right, slope is changing, slope is increasing, therefore it is ACCELERATING

d) Horizontal lines means the distance stays the same, but time is moving on, therefore its stationary

**1.3**know and use the relationship between average speed, distance moved and time:

Average speed = Total distance moved/time taken

v =
d t v x t = d t = dv |

**1.4**describe experiments to investigate the motion of everyday objects such as toy cars or tennis balls.

To measure the average velocity:-

a) Measure a metre with a metre rule and mark it on a table. Use a stop watch and time a ball rolling past the markers. To find the average speed divide the distance (1m) by the time. To reduce errors repeat the experiment and take the average of the readings before hand.

b) Set up two light gates and connect them to a timer or data logger. When the first light beam is broken by the car the timer starts. When the car passes the second beam of light the timer stops. Repeat this experiment to get more accurate results. Measure the distance between the light gates. You now have the time taken to reach and the distance. Velocity can be found by dividing the distance by the time.

c) You might need to describe motion with ticker tape.

Dots are made at 50 times a second, meaning each dot is 1/50s apart or 0.02s apart.

Knowing this you can work out the speed.

The time to produce 5 gaps in the dots is 5 x 0.02s = 0.1s. (so for this experiment, every 5 dots = 0.1s)

If you measured the distance of the 5 spaces, say 5cm ( 0.05m) you can now work out the speed.

speed = distance / time

speed = 0.05 m / 0.1s = 0.5m/s.

(Remember if you multiplied it by 3.6 you will get 1.8km/hr)

Notice

when the dots are evenly spaced you have constant velocity

when the dots are spreading out you have acceleration

Dots are made at 50 times a second, meaning each dot is 1/50s apart or 0.02s apart.

Knowing this you can work out the speed.

The time to produce 5 gaps in the dots is 5 x 0.02s = 0.1s. (so for this experiment, every 5 dots = 0.1s)

If you measured the distance of the 5 spaces, say 5cm ( 0.05m) you can now work out the speed.

speed = distance / time

speed = 0.05 m / 0.1s = 0.5m/s.

(Remember if you multiplied it by 3.6 you will get 1.8km/hr)

Notice

when the dots are evenly spaced you have constant velocity

when the dots are spreading out you have acceleration

**1.5**know and use the relationship between acceleration, velocity and time:

acceleration = change in velocity/time taken

*a*= (

*v*–

*u*)/

*t*

ex a car is travelling at 50 m/s and suddenly brakes for 2s until it comes to rest. What is its acceleration?

a =

a =

5

a = - 10 m/s2

so it has a negative acceleration

or deceleration

- what do we have
- initial velocity u = 50m/s
- final velocity v = 0m/s (comes to rest)
- time taken t = 5s

a =

__(v - u)__a =

__(0 - 50)__5

a = - 10 m/s2

so it has a negative acceleration

or deceleration

**1.6**plot and interpret velocity–time graphs

**1.7**determine acceleration from the gradient of a velocity–time graph

**1.8**determine the distance travelled from the area between a velocity–time graph and the time axis.

The distance travelled is the area under the graph

distance (for this graph) = area of triangle + area of rectangle

1/2 base x height + base x height

1/2 x 4 x 8 + 6 x 8

16 + 48

= 64m

**c) Forces, movement, shape and momentum**

1.9 describe the effects of forces between bodies such as changes in speed, shape or direction

If a car is accelerating, then the forward driving force is greater than the opposing drag and frictional forces.

moment = force × perpendicular distance from the pivot

● causes moons to orbit planets

orbital speed = (2 × π × orbital radius)/time period

● the universe is a large collection of billions of galaxies

● a galaxy is a large collection of billions of stars

● our solar system is in the Milky Way galaxy.

- Change in speed

If a car is accelerating, then the forward driving force is greater than the opposing drag and frictional forces.

- Change in shape

- Change in direction

**1.10**identify different types of force such as gravitational or electrostatic**1.11 distinguish between vector and scalar quantities****1.12 understand that force is a vector quantity****1.13 find the resultant force of forces that act along a line****1.14**understand that friction is a force that opposes motion**1.15**know and use the relationship between unbalanced force, mass and acceleration: force = mass × acceleration*F*=*m*×*a***1.16**know and use the relationship between weight, mass and*g*: weight = mass ×*g**W*=*m*×*g***1.17**describe the forces acting on falling objects and explain why falling objects reach a terminal velocity**1.18**describe experiments to investigate the forces acting on falling objects, such as sycamore seeds or parachutes**1.19**describe the factors affecting vehicle stopping distance including speed, mass, road condition and reaction time**1.20 know and use the relationship between momentum, mass and velocity:****momentum = mass × velocity***p*=*m*×*v***1.21****use the idea of momentum to explain safety features****1.22 use the conservation of momentum to calculate the mass, velocity or momentum of objects****1.23 use the relationship between force, change in momentum and time taken:****force = change in momentum/time taken****1.24 demonstrate an understanding of Newton’s third law****1.25**know and use the relationship between the moment of a force and its distance from the pivot:moment = force × perpendicular distance from the pivot

**1.26**recall that the weight of a body acts through its centre of gravity**1.27 know and use the principle of moments for a simple system of parallel forces acting in one plane****1.28****understand that the upward forces on a light beam, supported at its ends, vary with the position of a heavy object placed on the beam**

1.29describe experiments to investigate how extension varies with applied force for helical springs, metal wires and rubber bands1.29

**1.30**understand that the initial linear region of a force–extension graph is associated with Hooke’s law**1.31**describe elastic behaviour as the ability of a material to recover its original shape after the forces causing deformation have been removed.**d) Astronomy****1.32**understand gravitational field strength,*g*, and recall that it is different on other planets and the moon from that on the Earth**1.33**explain that gravitational force:● causes moons to orbit planets

- causes the planets to orbit the Sun
- causes artificial satellites to orbit the Earth
- causes comets to orbit the Sun

**1.34**describe the differences in the orbits of comets, moons and planets**1.35**use the relationship between orbital speed, orbital radius and time period:orbital speed = (2 × π × orbital radius)/time period

*v*= (2 × π ×*r*)/*T***1.36**understand that:● the universe is a large collection of billions of galaxies

● a galaxy is a large collection of billions of stars

● our solar system is in the Milky Way galaxy.