Which of these would be a typical speed for a racing cyclist travelling down a steep straight slope? A 0.2 m/s B 2 m/s C 20 m/s D 200 m/s A cyclist travels down a slope - Edexcel - GCSE Physics Combined Science - Question 4 - 2019 - Paper 1

The change in gravitational potential energy (GPE) can be calculated using the formula:

$\text{GPE} = m \cdot g \cdot h$

Where:

• $m$ is the mass (75 kg)
• $g$ is the gravitational field strength (10 N/kg)
• $h$ is the height (20 m)

Substituting the values: $\text{GPE} = 75 \text{ kg} \times 10 \text{ N/kg} \times 20 \text{ m} = 15000 \text{ J}$

Therefore, the change in GPE is 15000 J.

To find the distance travelled by the aircraft, we can use the equation:

$x = \frac{v^2 - u^2}{2a}$

Where:

• $v$ = final velocity (80 m/s)
• $u$ = initial velocity (0 m/s)
• $a$ = acceleration (4 m/s²)

Substituting the values: $x = \frac{(80)^2 - (0)^2}{2 \times 4} = \frac{6400}{8} = 800 \text{ m}$

Thus, the distance travelled by the aircraft is 800 m.

The extra piece of apparatus needed to determine the average speed is a stopwatch. The stopwatch will be used to measure the time taken for the trolley to travel between the two marks.

The student can make the trolley accelerate by attaching a string to it, which is connected to a weight hanging off the side of the bench. When the weight is released, it will pull the trolley forward, causing it to accelerate along the bench.

One other measurement the student must make is the time taken for the trolley to travel between the two marks. This will allow them to calculate the acceleration using the formula:

$a = \frac{\Delta v}{\Delta t}$

where $\Delta v$ is the change in velocity and $\Delta t$ is the time interval.