Physics Work and Energy Quiz

A 500N box is lifted 2m. Calculate how much work is done to lift the box.

A 50kg woman is running 10m/s. Calculate her KE.

A 80kg sky diver falls from 2000m to 1500m on Earth where gravity is 10N/kg. Calculate how much GPE she loses.

A spring is compressed 20cm and has a spring constant of 5N/m. Calculate the force used.

Calculate the stored elastic energy when a spring is compressed 15cm by a force of 5N. Use the formula: Work done = ½ x Force x Extension.

Explain how streamlining improves the efficiency of a vehicle.

Answer explanation

Streamlining reduces air resistance by allowing air to flow smoothly over the vehicle's surface. This decreased drag enhances fuel efficiency and speed, making the vehicle more efficient overall.

Describe the main ways energy is lost in a vehicle and how efficiency can be improved.

Answer explanation

Energy is lost in vehicles mainly through heat from friction, air resistance, and engine inefficiency. Improving efficiency can be achieved by reducing weight, enhancing aerodynamics, and using advanced engine technologies.

What is the purpose of the Hooke’s Law practical and what are the independent and dependent variables?

Answer explanation

The purpose of the Hooke’s Law practical is to investigate the relationship between force and extension in springs. The independent variable is the applied force, while the dependent variable is the extension of the spring.

What could I calculate from the graph?

Answer explanation

Spring constant using

Force / Extension

Or Work done in stretching using

1/2 x force x extension

Place these steps for a roller coasters energy changes in order

• Energy is lost as heat and sound

• At the bottom it has maximum KE and minimum GPE

• As it falls it loses GPE and gains KE

• Work is done by the motor and changed to gravitational energy

• At the top the coaster has maximum GPE and minimum KE