Physics Paper 2

What is the formula for calculating the change in gravitational potential energy?

• Mass × Speed × Time

• Mass × Gravitational Field Strength × Change in Vertical Height

• Force × Distance × Time

• Mass × Acceleration × Distance

Answer explanation

The correct formula for calculating the change in gravitational potential energy is Mass × Gravitational Field Strength × Change in Vertical Height. This reflects how energy changes with height in a gravitational field.

In the formula for gravitational potential energy, what does "m" stand for?

• Meters

• Mass

• Momentum

• Motion

Answer explanation

In the formula for gravitational potential energy, 'm' stands for mass. It represents the amount of matter in an object, which is crucial for calculating gravitational potential energy, unlike the other options provided.

What is the effect on gravitational potential energy if the gravitational field strength is increased?

• It decreases

• It increases

• It remains the same

• It becomes zero

Answer explanation

Gravitational potential energy (U) is given by U = mgh, where g is the gravitational field strength. If g increases, U also increases, assuming mass (m) and height (h) remain constant. Thus, the correct answer is that it increases.

What is the formula to calculate gravitational potential energy (GPE)?

• GPE = m x g x h

• GPE = m + g + h

• GPE = m / g / h

• GPE = m - g - h

Answer explanation

The correct formula for gravitational potential energy (GPE) is GPE = m x g x h, where m is mass, g is the acceleration due to gravity, and h is height. The other options do not represent the correct relationship.

If the gravitational force on another planet is 20 N/kg, how would it affect the gravitational potential energy (GPE) compared to Earth?

• GPE would be higher

• GPE would be lower

• GPE would be the same

• GPE would be zero

Answer explanation

Gravitational potential energy (GPE) is directly proportional to gravitational force. Since the gravitational force on this planet is 20 N/kg, which is higher than Earth's 9.81 N/kg, the GPE would also be higher.

What is the effect on gravitational potential energy (GPE) if both mass and height are doubled?

• GPE is quadrupled

• GPE is doubled

• GPE is halved

• GPE remains the same

Answer explanation

Gravitational potential energy (GPE) is calculated using the formula GPE = mgh. If both mass (m) and height (h) are doubled, GPE becomes (2m)(2h) = 4mh, which means GPE is quadrupled.

In the kinetic energy formula, what is squared?

• Mass

• Speed

• Kinetic energy

• Time

Answer explanation

In the kinetic energy formula, KE = 1/2 mv², it is the speed (v) that is squared. This means that the kinetic energy increases with the square of the speed, making speed the correct answer.

What is the role of the bench in the experiment?

• To provide a starting point for the toy car.

• To measure the speed of the toy car.

• To act as a barrier for the toy car.

• To weigh the toy car.

Answer explanation

The bench serves as a starting point for the toy car, allowing it to roll down and begin the experiment. This is essential for measuring distance and speed accurately.

What unit is used to measure force in the formula for work done?

• Joules (J)

• Meters (m)

• Newtons (N)

• Kilograms (kg)

Answer explanation

In the formula for work done, force is measured in Newtons (N). Work is calculated as force multiplied by distance, where force is the key component measured in Newtons.

A weightlifter lifts a 280 N barbell weight 1.5 m straight up. Calculate the work done.

• 420 J

• 280 J

• 560 J

• 140 J

Answer explanation

Work done is calculated using the formula: Work = Force x Distance. Here, Force = 280 N and Distance = 1.5 m. Thus, Work = 280 N x 1.5 m = 420 J. Therefore, the correct answer is 420 J.