Figure 10 shows a small steel ball held at a height, h, above the ground - Edexcel - GCSE Physics - Question 7 - 2021 - Paper 1
Question 7
Figure 10 shows a small steel ball held at a height, h, above the ground.
The ball is released and allowed to fall to the ground.
The height h is 1.4 m.
Calculate... show full transcript
Worked Solution & Example Answer:Figure 10 shows a small steel ball held at a height, h, above the ground - Edexcel - GCSE Physics - Question 7 - 2021 - Paper 1
Step 1
Calculate the time, t for the ball to reach the ground.
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Answer
To find the time it takes for the ball to reach the ground, we can use the formula:
t2=g2h
Substituting the values:
Height, h = 1.4 m
Acceleration due to gravity, g = 10 m/s²
Thus,
t2=102×1.4
Calculating this:
t2=102.8=0.28
To find t, take the square root:
t=0.28≈0.53s
Step 2
Suggest one reason why the students’ value for t is different from the calculated value.
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Answer
One possible reason for the different average value of t recorded by the students compared to the calculated value is that the students’ reaction times when using the stopwatch could have caused a delay in starting or stopping the timer.
Step 3
Suggest one improvement the students could make to their procedure so that their value for t is closer to the calculated value.
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Answer
One improvement could be to use electronic timing gates to measure the fall time accurately, thus minimizing human reaction time errors.
Step 4
Calculate the magnitude of the force exerted by the floor on the box.
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Answer
To find the force exerted by the floor on the box, we can use the formula for momentum change:
force=timechange in momentum
The momentum just before it hits the floor is 8.7 kg m/s and it takes 0.35 s to come to rest:
Thus,
force=0.358.7≈24.857 N≈25 N
Step 5
State the magnitude and direction of the force exerted by the box on the floor.
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Answer
The magnitude of the force exerted by the box on the floor is 25 N, and the direction is upwards, opposing the force of gravity.
Step 6
Calculate the mass of the ball.
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Answer
To find the mass of the ball, we can use the momentum formula:
momentum=m⋅v
Where momentum at point S is 0.40 kg m/s. First, we need to calculate the velocity (v) using:
v2=u2+2as
Where:
Initial velocity, u = 0 (the ball starts from rest)
Acceleration, a = 10 m/s²
Distance dropped, s = 3.8 m
Substituting the values:
= 76$$
Thus,
v = \sqrt{76} \approx 8.7 \, \text{m/s}.
Now substituting back to find mass:
$$0.40 = m \cdot 8.7 \
\Rightarrow m = \frac{0.40}{8.7} \approx 0.046 \, \text{kg}$$
