OCR A-Level Physics B H557
Planning
Implementing
Analysis
Evaluation
Practical Skills
Use of Apparatus and Techniques
Fundamental Data Analysis
Imaging and Signalling
Sensing
Mechanical Properties of Materials
Waves and Quantum Behaviour
Space, Time and Motion
Creating Models
Out Into Space
Our Place in the Universe
Matter: Very Simple
Matter: Hot or Cold
Electromagnetism
Charge and Field
Probing Deep Into Matter
Ionising Radiation and Risk
Out Into Space
Gravitational and kinetic energy changes
- 3 things to know
- Components 01, 02 and 03
Overview
Recall questions on the near-surface potential energy equation, work done by a force, why mass cancels in a landing speed, path independence, and areas under force–distance graphs.
What you need to know
Answer each one before you reveal it.
A 70 kg climber ascends 12 m. What is the gain in gravitational potential energy?
What relationship links work done, force and displacement?
Questions from this subtopic
Each one with the model answer underneath.
- 1
What equation gives the change in gravitational potential energy near the Earth's surface?
Model answer
The change is ΔE = mgΔh, where g is the gravitational field strength.
- 2
Why is mgh valid only close to the Earth's surface?
Model answer
It assumes the field strength g is constant, which is true only over heights small compared with the radius of the Earth.
- 3
A 70 kg climber ascends 12 m. What is the gain in gravitational potential energy?
Model answer
ΔE = mgh = 70 × 9.81 × 12 = 8.2 × 10³ J.
- 4
What relationship links work done, force and displacement?
Model answer
The work done is ΔE = FΔs, where the displacement is measured along the direction of the force.
- 5
Why is no work done when a force acts at right angles to the motion?
Model answer
There is no displacement in the direction of the force, so the product FΔs along that direction is zero.
- 6
A ball of mass 0.20 kg is dropped from 1.8 m. What is its speed on landing, ignoring air resistance?
Model answer
From mgh = ½mv², v = √(2 × 9.81 × 1.8) = 5.9 m s⁻¹.
Other ways to work this
The same content, four other ways.
What is inside Levo
Six ways to work the same material.
Every question in Out Into Space, on a schedule.
Attempt a question from memory, write the correct version, then attempt it again. Levo records the jump between your first attempt and your last, and brings each question back on the day you are due to forget it.
Or £46 a year, about £3.83 a month. Cancel anytime.