AQA AS Physics C9 Force And Momentum Kerboodle Answers

This page contains the AQA AS Physics P9 Force And Momentum Kerboodle Answers for revision and understanding of Force And Momentum. This page also contains the link to the notes and video for the revision of this topic. 

C9.1 Momentum and impulse AQA AS Physics C9 Force And Momentum Kerboodle Answers: Page No. 157

1.Ans- a i 1.2 x 10-18 kgms-1 ii0.050kgms-1 iii 14kgms-1 b i 6.0kg ii 20ms-1 2.Ans- a 3.6 x 105 kgms-1 b 60s 3.Ans- a 5.4 x 106 kgms-1 b 45 s 4.Ans- a9.0 x 103 kgms-1 b i -8.4 x 103 kg ms-1 ii 1.0 ms-1

9.2 Impact forces AQA AS Physics C9 Force And Momentum Kerboodle Answers: Page No. 160

1. a the initial momentum of the lorry 1600kg ms-1 b the force of the impact. 3200N 2. a the change of momentum of the car due to the impact 3000kgms-1 b the impact force. 7.5kN 3. a the change of momentum -4.2 x 10-23 kgms-1 b the force on the molecule. -1.9 x 10-13 N 4. -2.1 x 10-23 kgms-1

9.3 Conservation of momentum AQA AS Physics C9 Force And Momentum Kerboodle Answers : Page No. 163

1. 0.72 m s-1 2. 0.7ms-1 in the same direction 3 . 0.05 m s-1 in the direction the 1.0 kg trolley was l 1.0 x 107m2 moving in 4. -0.63 m s-1 in the opposite direction to its initial direction.

9.4 Elastic and inelastic collisions AQA AS Physics C9 Force And Momentum Kerboodle Answers: Page No. 165

1.a i it rebounds to the same height ii it rebounds to a lesser height. In aii, the ball is released from a height of 1.20m above the surface and it rebounds to a height of 0.90 m above the surface. Show that of its kinetic energy is lost in the impact, 2. a the velocity of the vehicles immediately after impact 9.0ms-1 in the same direction b the loss of kinetic energy due to the impact. 24kJ 3.a the speed and direction of the 1.0 kg ice puck after the collision 1.1 ms-1 in the reverse direction b the loss of kinetic energy due to the collision. 20J 4. a’i 1.0 ms-1 ii Show that the collision was an elastic collision. b The driver of the 250kg car experiences a force from his/her car which slows him/her down; the other driver experiences a force from his/her car that accelerates him/her.

9.5 Explosions AQA AS Physics C9 Force And Momentum Kerboodle Answers : Page No. 167

1 .0.35 ms-1 2. a 0.25ms-1 ;the mass of A and X was greater 1 than the mass of B. so B moved away faster. b Show that the mass Of X must have been 0.10 kg. 3. a i 0.10 ms-1 ii15 mJ b 0.19ms-1 4.a the speed at which the rock was thrown from the boat 9.0ms-1 b the kinetic energy gained by i the boat 1.1 J ii the rock. 81 J

Practice questions: Page No. 168-169

1. (a)In an inelastic collision, kinetic energy is not conserved (b) (i) the momentum of the ball before the collision Momentum p = mv gives p = 0.12 × 18 = 2.16 N s (or kg m s-1) (ii) the momentum of the ball after the collision p = 0.12 × (−15) = −1.8 N s (or kg m s-1 ) (iii) the total change of momentum of the ball Change in momentum = 2.16 − (−1.8) = 3.96 N s (or kg m s-1 ) (iv) the average force acting on the ball during contact With the bat (v) the kinetic energy lost by the ball asa result 01 the collision. 2 . (a) (b) Impulse = change of momentum ∴0.135 = mA × 0.60 from which mA = 0.225 kg or 0.22 kg or 0.23 kg (c) The final total momentum of the system is zero 3.(a) Calculate the momentum of the engine. p = mv = 6.2 × 104 × 0.35 = 2.17 × 104 N s (or kg m s−1 ) or 2.2 × 104 N s (b) Initial momentum of engine = combined momentum after coupling ∴2.17 × 104 = 10.2 × 104 v gives v = 0.213 m s-1 or 0.21 m s-1 4. (a) ) Two quantities that are conserved: • momentum • kinetic energy (b) A gas molecule makes an elastic collision with the walls of a gas cylinder. The molecule is travelling at 450ms—l at right angles towards the wall before the (i) Magnitude of velocity is 450 m s−1 The direction is away from the wall at 90 ° to it (or in the opposite direction to the initial velocity). (ii) (c) • Force is exerted on the molecule by the wall • Molecule experiences a change in its momentum • Molecule must exert a force on the wall which is equal and opposite to the force produced by the wall on the molecule, by Newton’s third law of motion 5.(a) b (i) (ii) 6 (a) The shaded area represents impulse (or change in momentum). (b) 7.(a) The total momentum of a system of objects remains constant provided that no external resultant force acts on the system (b) (i) (ii) (iii) Banner 7

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