Work Done & Energy Transfer Practice Questions

Write down the equation which links distance ($s$), force ($F$) and work done ($W$).

The gardener pushes the wheelbarrow a distance of $24\ \text{m}$ along the path.

Calculate the work done by the gardener.

Work done = .............................. J

Which of the following is the same as $1$ joule?

Tick (✓) one box.

• $1\ \text{N}/\text{m}$
• $1\ \text{N}\,\text{m}$
• $1\ \text{N}\,\text{m}^2$
• $1\ \text{N}/\text{m}^2$

A mechanic does $250\ \text{N}\,\text{m}$ of work turning a bolt with a spanner.

Write down this amount of work done in joules.

Work done = .............................. J

A student slides a book across a desk. The student applies a horizontal force of $3.0\ \text{N}$ and the book moves $45\ \text{cm}$.

Calculate the work done on the book.

Work done = .............................. J

The weightlifter raises the barbell through a vertical distance of $2.1\ \text{m}$ at a steady speed.

Calculate the work done on the barbell by the weightlifter.

Work done = .............................. J

Describe the energy transfer that takes place while the barbell is being lifted.

Calculate the work done by the horse when the barge travels a distance of $2.4\ \text{km}$.

Work done = .............................. J

The barge travels at a constant speed, so its kinetic energy store does not change.

Explain why the work done by the horse causes the temperature of the water and of the barge to increase.

Calculate the work done when $600\ \text{g}$ was added to the block, and complete the table.

Write a conclusion for the student's investigation.

After the student had completed all of the tests, the bottom of the block and the surface of the bench were warmer than at the start.

Explain why.

The motor does $114\,000\ \text{J}$ of work raising the lift at a steady speed.

Calculate the height the lift is raised.

Height = .............................. m

Describe the energy transfers that take place as the lift is raised.

At the bottom of the slope the child and sledge are moving at $9.0\ \text{m/s}$.

gravitational field strength = $9.8\ \text{N/kg}$

Calculate the average frictional force acting on the sledge as it slides down the slope.

Average frictional force = .............................. N