Mark Scheme

Qn Answer Remarks Qn Answer Remarks

1 A Major misconceptions: Ohm and Newton are NOT base units.

6 A Major misconceptions: Free Body diagram not drawn properly, cannot set up equation of motion to solve for answer.

2 D 7 B Major misconception: Could not identify the Newtons 3rd Law pair of forces.

3 B 8 B

4 C 9 C

5 C 10 D

If units are not indicated, subtract 1 mark overall for each mistake made. If s.f. are not reported correctly (2 or 3 s.f.), subtract 1 mark overall.

Qn Suggested Answer Marks Remarks

1(a) Scalar magnitude only Vector magnitude and direction

B1

1(b) 10 N (+5%) in the direction of 37 (+5%) (or 53 (+5%)) degrees from vertical or 53 (or 37) degrees from horizontal Correct parallelogram OR tip to tail diagram

A1 A1

C1

2 (a) 0.01 mm B1

2 (b) - 0.04 mm B1

2 (c) 2.5 + 0.46 = 2.96 mm B1

2 (d) 2.96 ( 0.04) = 3.00 mm B1

3 (a) Ball is falling towards the ground with increasing velocity / speed / constant acceleration

B1

3 (b) The area above the AB graph is greater B1 Cannot identify the area under

than the area under the CD graph a v-t graph can show the distance travelled.

3 (c) (i) | Vf-Vi | = |5.0 5.3| = 0.3 (accept 0.2) m/s B1 Values are read wrongly.

3 (c) (ii) Vf Vi = 5.0 (5.3) = 10.3 (accept 10.2) m/s

B1 Values are read wrongly.

3 (c) (iii) Change in velocity / time taken = 10.3 / 0.05 = 206 m s-2. (accept 204, accept answers without units)

B1 Values are read wrongly. The gradient of a v-t graph gives the

acceleration.

4 Draw the forces on the nail correctly Draw the forces on the frame correctly

B1 B1

Cannot draw the free body diagram at different points in the diagram.

Correct diagram drawn (either nail or frame)

Forces & direction labeled correctly 5.8 N to 6.0 N

B1 B1 B1

Cannot set up the tip-to-tail diagram.

5 (a) Mass measure of the amount of substance in a body Inertia Mass of a body is the property that resists a change in the state of rest or motion. Gravitational Mass of a body is the property of matter that creates and responds to gravitational forces.

Any one B1

Weight force on the object due to gravity B1

5 (b)(i) W and N arrows are drawn correctly N is drawn longer than W

B1 B1

Cannot draw the forces at the appropriate places and the length of

the arrows are not proportional to the magnitude.

5(b)(ii) Make the statement: ma = N W N = ma + mg = 80 x 2 + 800 Substitute the values into the equation 960 N

C1 C1 A1

Cannot set up the equation of motion (Fnet = ma).

6(a)(i) Weight or gravitational force due to earth B1

6(a)(ii) 10 or 9.8 or 9.81 m s-2. B1 Conceptual: Acceleration is the gradient of a v-t graph. Not reading off a v-t graph.

6 (a)(iii) Air resistance or Drag or Resistive force B1

6(a)(iv) After the speed increases, the air resistance/drag increases because Fd=k.v, where k is a constant. The net force and hence net acceleration decreases.

B1

B1

6(a)(v) At a point where Fd=W, the parachutist falls at a constant velocity

B1

6(b)(i) The parachute canopy is bigger, air resistance increases and the parachutist falls at a lower speed.

B1

6(b)(ii) 0 m s-2. B1

6(b)(iii) Shape of graph must be totally correct.

Label the graph with A, B, C, D.

M1 A1

Need to understand that the a-t graph is the gradient of the v-t

graph.