Energy & Work

🔗 A) Match the Concept with the Description

Match each concept with its correct description.

Options:

A. Energy stored due to position or height
B. Energy related to motion
C. Transfer of energy when a force moves an object
D. Combination of kinetic and potential energy
E. Push or pull applied to an object
F. Change in position in a specific direction

📐 B) Kinetic and Potential Energy Calculations

Use:

Kinetic Energy = (1/2)mv²

Potential Energy = mgh

Take g = 10 m/s².

1. A 4 kg object moves at 5 m/s.

   • Find its kinetic energy.

2. A 3 kg object is lifted to a height of 8 m.

   • Find its gravitational potential energy.

3. A 2 kg ball is at a height of 10 m.

   • Find its potential energy.

   • If all potential energy becomes kinetic energy, what is its kinetic energy at the bottom?

🧠 C) Interpret the Result

A student says:

“If an object is not moving, it has no energy.”

Answer:

1. Is the statement correct?

2. Give one example where an object is not moving but still has energy.

3. What type of energy does it have?

💪 D) Work or No Work?

For each situation, decide if physical work is done. Justify.

1. A student pushes a wall, but the wall does not move.

2. A box is pushed 4 m across the floor.

3. A person holds a heavy backpack without moving.

4. A crane lifts a load upward.

5. A ball rolls after being kicked.

🧮 E) Work Calculations

Use:

Work = Force × Distance

1. A force of 25 N pushes a box 6 m.

   • Work = ______

2. A student applies 40 N to move a desk 3 m.

   • Work = ______

3. A force of 15 N is applied, but the object does not move.

   • Work = ______

   • Explain why.

🔥 F) Integrated Challenge

A force of 30 N pushes a 3 kg box along 5 m.

1. Calculate the work done.

2. If all the work becomes kinetic energy, what is the kinetic energy of the box?

3. Use KE = (1/2)mv² to estimate the final speed.

4. Does your result make physical sense? Explain.

🧩 G) Hierarchy Task

Complete the hierarchy:

Energy
→ Mechanical Energy
→ __________ and __________
→ Energy transformation
→ Work as __________ transfer

Then write one example that shows this hierarchy in real life.