Work
Which statement correctly defines work done?
A student lifts a bag of books weighing 40 N from the floor to a shelf 1.5 m above the floor. Calculate the work done by the student on the bag.
A horizontal force does 7200 J of work pushing a box 90 cm along a floor. Calculate the applied force.
A person holds a 200 N suitcase stationary while waiting for a bus. Which statement correctly describes the work done by the person on the suitcase?
A tractor pulls a log 350 m across a field with a constant horizontal force of 800 N. The work done is then used to calculate the energy transferred. What is the energy transferred?
A force of 500 N pushes a crate 12 m across a floor. The force is then reduced to 250 N and the crate is pushed a further 12 m. What is the total work done over the entire 24 m?
Which quantity has the same SI unit as work done?
A delivery robot does 4500 J of work moving a parcel. The applied force is 150 N. Calculate the distance the parcel moves in the direction of the force.
A cyclist rides 2.0 km along a flat road against a constant air resistance of 35 N. Calculate the work done against air resistance.
A warehouse worker pushes a crate with a horizontal force of 600 N across 5.0 m of floor, then up a ramp using the same force through a distance of 3.0 m along the ramp. What is the total work done by the worker?
An electric motor does 1500 J of electrical work to lift a crate. The crate gains 1200 J of gravitational potential energy. State the amount of energy transferred to thermal stores.
A car engine does 54 000 J of work against friction over a journey. The friction force is constant at 600 N. Determine the distance over which this friction force acts.
A spring-loaded toy car is released and travels 0.80 m across a table. The elastic potential energy stored in the spring before release was 0.60 J. Assuming all energy is transferred to work done against friction, calculate the average friction force acting on the car.
A force of 120 N is applied horizontally to a box, but the box does not move because static friction prevents it. Which row correctly gives the work done and the energy transferred?
Two identical boxes are placed on different surfaces. Box X is pushed 4.0 m across a rough surface by a force of 300 N. Box Y is pushed 4.0 m across a smooth (frictionless) surface by a force of 300 N. Which statement correctly compares the work done on the two boxes?