The Required Practical Assessment

What is the independent variable in the reaction time investigation?

The consumption of a stimulant like caffeine or the person being tested.

What is the dependent variable in the reaction time investigation?

Reaction time, measured by the distance the ruler falls before being caught.

What should be kept consistent as a control variable when measuring reaction time?

Using the same person to catch the ruler or maintaining the position of the forearm and fingers.

What equation relates distance, acceleration, and time in the gravity response of a ruler drop?

s = (1/2)gt², where 's' is distance, 'g' is acceleration due to gravity, and 't' is time.

How do you calculate average reaction time from multiple measurements?

Sum all reaction time measurements and divide by the number of measurements.

What is Hooke's Law?

The extension of a spring is directly proportional to the force applied to it, expressed as F = kx.

What is the purpose of using a ripple tank in the investigation of wave speed?

To measure the speed of water waves.

In the investigation of waves on a string, how can the wave speed be calculated?

Using the wave equation v = f × λ, where v is the wave speed, f is the frequency, and λ is the wavelength.

What affects the wave speed on a string during the practical investigation?

The tension in the string and its mass per unit length.

What type of surfaces are best for absorbing infrared radiation in the Leslie cube experiment?

Matte black surfaces are the best absorbers of infrared radiation.

What is the relationship illustrated in a force vs. acceleration graph according to Newton's second law?

A linear relationship passing through the origin.

What is a key source of error when measuring the wavelength of waves in a ripple tank?

Parallax error when reading measurements on the screen.

What should you do to ensure a fair test when investigating the emission of infrared radiation from different surfaces?

Hold the thermometer at the same distance and angle from each surface.

What does the gradient of the force vs. extension graph represent for a spring?

The spring constant (k) of the spring.

How can you minimize the effects of friction in the trolley experiment?

Use a frictionless track where applicable and ensure trolley wheels move freely.

What happens if a spring is stretched beyond its elastic limit?

It will not return to its original length, and Hooke's Law no longer applies.

Why is it important to keep control variables consistent during the experiments?

To ensure a fair test so that only the independent variable affects the dependent variable.