Measuring energetic change

When the ball is thrown upward, it is moving — so it starts with kinetic energy (the energy of motion).

As the ball rises, it slows down (losing kinetic energy) and gains height (gaining gravitational potential energy). These two changes happen simultaneously.

By the law of conservation of energy, the kinetic energy is not destroyed — it is converted into gravitational potential energy. At the very top, the ball is momentarily stationary, so all remaining energy is gravitational potential energy.

The transformation is: kinetic energy → gravitational potential energy. This matches the first option.

The question asks which energy transformation occurs as a thrown ball rises upward. We need to identify the starting energy form and what it converts into.

This is the reverse transformation — it describes what happens as the ball falls, not rises. The ball is gaining height, not losing it.

Chemical energy is stored in fuels and food. A thrown ball does not involve a chemical reaction — there is no burning or chemical change occurring.

Elastic potential energy is stored in stretched or compressed objects like springs. A thrown ball is not a spring or elastic object, so this transformation does not apply.

The only remaining option — kinetic energy converts to gravitational potential energy — correctly describes a moving ball slowing down and gaining height.

Work done is calculated using: $W=F\times d$ where $F$ is the force in newtons and $d$ is the distance moved in the direction of the force in metres.

The force applied is $F=120\text{N}$ and the distance is $d=5\text{m}$. The mass of the crate (30 kg) is not needed for this calculation — work done depends on force and distance, not mass directly.

$W=120\times 5=600\text{J}$

The worker does 600 J of work on the crate.

The question asks for work done using a 120 N force over 5 m. The correct formula is $W=F\times d$.

$1,500\text{J}$ would result from $30\times 5\times 10=1,500\text{J}$, which uses $W=mgh$ — a formula for lifting against gravity, not pushing horizontally. The 30 kg mass is a distractor here.

$300\text{J}$ would result from $120\times 5÷2=300$, which incorrectly halves the answer. There is no reason to divide by 2 in this scenario.

$3,600\text{J}$ would result from $120\times 30=3,600$, which multiplies force by mass — this is not the work done formula.

Applying $W=F\times d=120\times 5=600\text{J}$ gives the correct answer.