4 (a) Which of these is a unit of momentum? A kg/m/s B kg/m/s C kg/m/s² D kg/m/s² (b) Students investigate conservation of momentum using two identical trolleys. A card is then added to trolley A. Some of the apparatus is set up as shown in Figure 4. (i) Describe an investigation the students could carry out to show that momentum is conserved when these two trolleys collide. You may add to the diagram to help with your answer. (ii) Give a reason for the runway being at a slope. (c) Figure 5 shows a racket and a tennis ball. The tennis ball is travelling towards the racket at a velocity of 8.2 m/s. The ball is hit back in the opposite direction at a velocity of 15 m/s. The ball has a mass of 0.075 kg. The ball is in contact with the racket for 12 ms. (i) Calculate the average force exerted by the ball on the racket. Use the equation F = mv - mu / t (ii) Describe how Newton’s Third Law of Motion applies to the collision between the racket and the ball.

Photo AI

4 (a) Which of these is a unit of momentum? A kg/m/s B kg/m/s C kg/m/s² D kg/m/s² (b) Students investigate conservation of momentum using two identical trolleys - Edexcel - GCSE Physics Combined Science - Question 4 - 2022 - Paper 1

Question 4

4 (a) Which of these is a unit of momentum? A kg/m/s B kg/m/s C kg/m/s² D kg/m/s² (b) Students investigate conservation of momentum using two identical trolleys... show full transcript

Worked Solution & Example Answer:4 (a) Which of these is a unit of momentum? A kg/m/s B kg/m/s C kg/m/s² D kg/m/s² (b) Students investigate conservation of momentum using two identical trolleys - Edexcel - GCSE Physics Combined Science - Question 4 - 2022 - Paper 1

Step 1

(b)(i) Describe an investigation the students could carry out to show that momentum is conserved when these two trolleys collide.

96%

114 rated

Answer

To investigate the conservation of momentum, the students can set up an experiment using two identical trolleys on a frictionless track. They can attach a card to trolley A and ensure both trolleys are stationary before the experiment begins.

Initial Setup: Position the trolleys apart on the track, with trolley A having a card and trolley B empty, as shown in Figure 4.
Collision: Release trolley A so that it collides with trolley B. This will allow the students to observe the transfer of momentum during the collision.
Measurement: Use a stopwatch to measure the time of contact between the two trolleys and note the velocities of both trolleys before and after the collision.
Analysis: Calculate the momentum of both trolleys before and after the collision using the formula: momentum = mass × velocity, and compare these values to confirm whether momentum is conserved.

Step 2

(b)(ii) Give a reason for the runway being at a slope.

99%

104 rated

Answer

The runway is sloped to prevent the trolleys from slowing down due to friction. By inclining the runway, you ensure that trolley A can travel at a constant speed without the interference of friction, allowing for a more accurate measurement of momentum during the collision.

Step 3

(c)(i) Calculate the average force exerted by the ball on the racket.

96%

101 rated

Answer

To calculate the average force exerted by the ball on the racket, we can use the formula:
$F = \frac{mv - mu}{t}$

Where:

$m = 0.075 \, \text{kg}$ (mass of the ball)
$v = 15 \, \text{m/s}$ (final velocity)
$u = 8.2 \, \text{m/s}$ (initial velocity, in the opposite direction)
$t = 0.012 \, \text{s}$ (time in contact with the racket)

Calculating:

Substitute values into the formula: $F = \frac{(0.075 \cdot 15) - (0.075 \cdot 8.2)}{0.012}$
Simplifying leads to: $F = \frac{(1.125 - 0.615)}{0.012}$
This yields: $F = \frac{0.51}{0.012} = 42.5 \text{N}$ Thus, the average force exerted by the ball on the racket is 42.5 N.

Step 4

(c)(ii) Describe how Newton’s Third Law of Motion applies to the collision between the racket and the ball.

98%

120 rated

Answer

Newton’s Third Law states that for every action, there is an equal and opposite reaction. In the context of the collision between the racket and the ball:

When the ball strikes the racket, it exerts a force on the racket.
Concurrently, the racket exerts an equal and opposite force back on the ball. This interaction highlights that the forces are equal in size but opposite in direction, demonstrating the principles of Newtonian mechanics.

4 (a) Which of these is a unit of momentum? A kg/m/s B kg/m/s C kg/m/s² D kg/m/s² (b) Students investigate conservation of momentum using two identical trolleys - Edexcel - GCSE Physics Combined Science - Question 4 - 2022 - Paper 1

Worked Solution & Example Answer:4 (a) Which of these is a unit of momentum? A kg/m/s B kg/m/s C kg/m/s² D kg/m/s² (b) Students investigate conservation of momentum using two identical trolleys - Edexcel - GCSE Physics Combined Science - Question 4 - 2022 - Paper 1

(b)(i) Describe an investigation the students could carry out to show that momentum is conserved when these two trolleys collide.

(b)(ii) Give a reason for the runway being at a slope.

(c)(i) Calculate the average force exerted by the ball on the racket.

(c)(ii) Describe how Newton’s Third Law of Motion applies to the collision between the racket and the ball.

Join the GCSE students using SimpleStudy...