Form 3 Science Bab 7: Energy and Power
Instructions
Answer all questions based on Chapter 7: Energy and Power.
10 questions · 22 marks total
1. A coconut of mass 1.5 kg falls from a tree from a height of 8 m to the ground (g = 10 m/s2: (a) Calculate the gravitational potential energy of the coconut before it falls. (b) Assuming no air resistance, determine the kinetic energy and velocity of the coconut just before hitting the ground.
Short Answer · 4m2. True or False: If a person carries a heavy suitcase and stands completely stationary for 10 minutes, no work is done on the suitcase in terms of physics.
True / False · 1m3. Two athletes, Athlete A (mass 60 kg) and Athlete B (mass 80 kg), climb the same height of 10 m up a hill. Athlete A reaches the top in 20 seconds while Athlete B takes 25 seconds (g = 10 m/s2. (a) Calculate the work done by each athlete against gravity. (b) Determine which athlete generates higher power.
Short Answer · 4m4. State two factors that affect the gravitational potential energy stored in an object near Earth's surface.
Short Answer · 2m5. State the Principle of Conservation of Energy and explain how energy conversion occurs in a simple swinging pendulum.
Short Answer · 3m6. A force of 60 N is used to pull a trolley over a horizontal distance of 5 m in 10 seconds. Calculate: (a) The work done. (b) The power generated.
Short Answer · 2m7. A spring with an original length of 15 cm stretches to 20 cm when a load of 10 N is hung from it. Calculate the elastic potential energy stored in the stretched spring.
Short Answer · 3m8. Fill in the blank: The rate at which work is done or energy is transferred is called ____________.
Fill in the Blank · 1m9. True or False: According to the Principle of Conservation of Energy, energy can be created when an object accelerates downwards freely.
True / False · 1m10. Which mathematical formula correctly represents kinetic energy (Ek)?
Multiple Choice · 1m