9 -2

http://twyfordigcsephysics.blogspot.co.uk/2012/12/investigating-newton-2.html

http://twyfordigcsephysics.blogspot.co.uk/2012/12/experimental-results.html

9-1

http://twyfordigcsephysics.blogspot.co.uk/2012/12/investigating-newton-2.html

http://twyfordigcsephysics.blogspot.co.uk/2012/12/experimental-results.html

9-1

Lesson notes at the end of this post

http://twyfordigcsephysics.blogspot.co.uk/2012/11/blog-post.html

Answers to calculations on force

1. 1.       F= ma = 2000 x 3 = 6000 N
2. 2.       F= ma = 90 x (-4) = -360 N
3. 3.       F= ma = 0.05 x (-60) = -3 N
4. 4.       F = ma = 10 000 000 kg x 10 = 100 000 000 N = 1 x 10⁸ N
5. 5.       F = ma = 70 x (-14) =- 980 N
6. 6.       F= ma = 1000 x (-50) =- 50 000 N
7. 7.       F = ma = 0.1kg x 5 = 0.5 N

1a           -2.5m/s²                                         b             -2500N

2a           5m/s²                                    b             450 N

3a           0.25m/s²              `                 b             3N

4a           - 1500 m/s²                            b             -30 N

5              500kg

6              10m/s²

7              a = - 3m/s                                          -2250 N

9-2 (27/11 and 28/11)

http://twyfordigcsephysics.blogspot.co.uk/2012/11/blog-post.html

9-1

Newton's Laws (part 1)

9 -1

Acceleration due to gravity

9 set 2 Acceleration

Acceleration

http://twyfordigcsephysics.blogspot.co.uk/2012/10/acceleration.html

Ticker timer Traces

http://twyfordigcsephysics.blogspot.co.uk/2012/10/ticker-timer-traces.html

Displacement-time graphs

http://twyfordigcsephysics.blogspot.co.uk/2012/10/displacement-time-graphs.html

9 Set 1 Acceleration

http://twyfordigcsephysics.blogspot.co.uk/2012/10/acceleration.html

Velocity - time graphs

http://twyfordigcsephysics.blogspot.co.uk/2012/11/velocity-time-graphs.html

Vectors and Scalars

http://twyfordigcsephysics.blogspot.co.uk/2012/09/vectors-and-scalars.html

Speed

http://twyfordigcsephysics.blogspot.co.uk/2012/09/speed.html

Quantities and units

http://twyfordigcsephysics.blogspot.co.uk/2012/09/units.html

http://twyfordigcsephysics.blogspot.co.uk/2012/09/quantities-and-units.html

space

http://twyfordigcsephysics.blogspot.co.uk/2013/07/space.html

orbital speed questions

http://twyfordigcsephysics.blogspot.co.uk/2013/07/answers-to-orbital-speeds-worksheet.html

Orbits

http://twyfordigcsephysics.blogspot.co.uk/2013/06/orbital-speeds.html

Gravity

http://twyfordigcsephysics.blogspot.co.uk/2013/06/gravity.html

mark scheme for the first part of the questions

Revision Tracker for Y9

This is for the whole year.. You won't be examined on topics we have yet to do.

http://twyfordigcsephysics.blogspot.co.uk/p/revision.html

Stretching a Wire

http://twyfordigcsephysics.blogspot.co.uk/2013/05/stretching-wire.html

Mark Scheme assessed homework

1.       (a)     friction                                             if more than one box is ticked, award   1 (L3)
                                                         no mark

(b)     (i)      it gets longer                            accept ‘it is more’                                 1 (L3)

(ii)     any one from                                                                                       1 (L4)

·   there is less friction or grip

·   the road is slippery             accept ‘water is a lubricant’

(iii)    it gets longer                            accept ‘it is more’                                 1 (L3)

(iv)    concrete                                                                                               1 (L4)

[5]

  2.     (a)     one mark is for the correct value and the other mark is for the corresponding unit

either

·   1500                                            accept ‘100 × 15’                                 1 (L7)

·   N cm or newton cm                                                                                  1 (L7)

or

·   15                                                accept ‘100 × 0.15’

·   N m or newton metre

  (b)   exert a larger force                           answers may be in either order             1 (L7)

accept ‘use a bigger force’ or ‘push harder’
do not accept ‘exert a larger pressure’

          exert the force further away from the nut                                                      1 (L7)

accept ‘push down further from the nut’ or ‘exert the force further along the spanner’
do not accept ‘use of a longer spanner’

[4]

  3.     (a)     down                                                                                                             1 (L3)

(b)     B and D                                            letters may be in either order both        1 (L3)
                                                         letters are required for the mark

accept 112 and 112

  (c)   down                                                                                                             1 (L3)

(d)     E                                                                                                                    1 (L3)

(e)     any two from                                                                                                2 (L4)

·   put the gold coin in one pan and a silver coin or coins in the other

·   add or replace or remove silver coins

·   see which pan goes up or see which way the scales move

accept ‘see if it balances’

·   it is heavier than the silver coins which go up

·   it is lighter than the silver coins which go down

accept ‘try each silver coin to see which one balances the gold coin’ for two marks

[6]

  4.     (a)     (i)      75                                           accept ‘50 × 1.5’                                  1 (L7)
Nm                                                                                                       1 (L7)

do not accept lower case n

(ii)     750                                         accept ‘‘ or ‘50 × 15’              1 (L7)
                                               accept the numerical answer to part (i) ÷ 0.1

  (b)   any one from                                                                                                 1 (L7)
·  a current flows in the coil
·  the coil or the iron core                accept ‘there is a magnetic field’ or ‘the
   becomes magnetised                     electromagnet switches on

do not accept ‘the core becomes magnetic’

          any one from                                                                                                 1 (L7)
·  the counterweight is attracted
   to the coil or core or the
   electromagnet
·  the electromagnet produces a       accept ‘the left-hand side of the barrier
   bigger moment                              moves down’

‘the right-hand side moves up’ is insufficient

[5]

5.       (i)      (when a system is in equilibrium) the sum of the anticlockwise
moments equals the sum of the clockwise moments (about the same pivot)         B1

(ii)     sum of the forces equals zero / resultant force is zero                                          B1
sum of the moments equals zero      B1

[3]

6.       (sum of) clockwise moment(s) = (sum of )
anticlockwise moment(s)

Not: ‘CWM = ACWM’

C1

          (18 × 0.14) + (60 + 0.32) = 0.035F

Allow: working in consistently in cm

C1

          F ≈ 620 (N)

Note: Bald answer scores 3 marks
Allow: 1 mark for 21.72 (N m) or 2172 (N cm)

A1

[3]

 7.      (a) Any three from:
1. (Suspend plate from a point and then) mark a
    vertical line on the plate (wtte)
2. Plumb line / ‘pendulum’ (used to find the vertical
    line)
3. Hang from another point / place (and draw
    another vertical line) (wtte)
4. Where the lines intersect gives position of centre
    of gravity (wtte)

Note: For 1st point accept ‘mark line of string’

Allow: 1 mark for ‘By trial and error find a position where the plate balances’

B1 × 3

          (b) (i) moment = 6.0 × 0.40
moment = 2.4 (N m)

B1

(ii)     Weight / force acts through the pivot
Or (perpendicular) distance from pivot is (reduced to)
zero (wtte)

Allow: weight is ‘vertically below’/‘directly below’ the pivot
Reference to pivot / point P (wtte) is essential

B1

[5]

Elasticity

http://twyfordigcsephysics.blogspot.co.uk/2013/05/elasticity.html

Moments and Bridges

http://twyfordigcsephysics.blogspot.co.uk/2013/04/moments-and-bridges.html

Moments Homework

http://twyfordigcsephysics.blogspot.co.uk/2013/04/moments-homework-answers-plus-hints.html

Centre of gravity

http://twyfordigcsephysics.blogspot.co.uk/2013/04/centre-of-gravity.html

Moments

http://twyfordigcsephysics.blogspot.co.uk/2013/03/moments.html

Levers

http://twyfordigcsephysics.blogspot.co.uk/2013/03/the-lever.html

February Assessment

http://twyfordigcsephysics.blogspot.co.uk/2013/02/february-assessment.html

Momentum and car safety

http://twyfordigcsephysics.blogspot.co.uk/2013/02/momentum-and-car-safety.html

Forces on a Plane

Collisions

1.       A truck of mass 2kg travels at 8 m/s towards a stationary truck of mass 6kg. After the collision they stuck together and move off in the same direction. What is their common velocity?

2.       A car of mass 2000kg, traveling at 10m/s, has a head on collision with a small sports car of mass 500kg. If both cars stop dead on colliding, what was the velocity of the sports car before the collision?

3.       A man wearing a bullet proof vest stands on roller skates. His total mass is 80kg. A bullet of mass 20g is fired at him at a speed of 400 m/s. If the bullet is stopped by the vest and falls to the ground, what velocity will the man move at? How does your answer compare with “the movies”?

Momentum

http://twyfordigcsephysics.blogspot.co.uk/2013/02/momentum.html

Stopping Distances

http://twyfordigcsephysics.blogspot.co.uk/2013/01/stopping-distances.html

Terminal Velocity Experiment

http://twyfordigcsephysics.blogspot.co.uk/2013/01/terminal-velocity.html