__ 8. A car (mass=1200kg) moves at 10m/s. Calculate the mechanical kinetic energy of the car. a. 6000J b. 60000J c. 12000J d. 720000001 __ 9. If a pendulum is raised to a height of 3.0 metres above its lowest point and has 147J of gravitational potential energy, what is the mass of the pendulum? Assume that the acceleration due to gravity is 9.8m/s^2 a. 5.0 kg b. 15 kg c. 49 kg d. 98 kg __ 10. A ball (m=2kg) is thrown, giving it a mechanical kinetic energy of 64 J. Calculate the velocity of the ball. a. 4m/s b. 8m/s c. 16m/s d. 64m/s Short Answer 11. Describe one energy transformation involved when boiling water in a kettle. 12.Calculate the mechanical kinetic energy of a car (m=800kg) moving at 15m/s. Show all your work and use appropriate units.

**8.**<br /><br />The formula for kinetic energy is KE = (1/2)mv².<br /><br />KE = (1/2) * 1200 kg * (10 m/s)²<br />KE = (1/2) * 1200 kg * 100 m²/s²<br />KE = 60000 J<br /><br />The answer is **b. 60000J**<br /><br />**9.**<br /><br />The formula for gravitational potential energy is PE = mgh.<br /><br />147 J = m * 9.8 m/s² * 3.0 m<br />147 J = 29.4 m/s² * m<br />m = 147 J / 29.4 m/s²<br />m = 5.0 kg<br /><br />The answer is **a. 5.0 kg**<br /><br />**10.**<br /><br />The formula for kinetic energy is KE = (1/2)mv².<br /><br />64 J = (1/2) * 2 kg * v²<br />64 J = 1 kg * v²<br />v² = 64 m²/s²<br />v = √(64 m²/s²)<br />v = 8 m/s<br /><br />The answer is **b. 8m/s**<br /><br />**Short Answer**<br /><br />**11.** One energy transformation involved in boiling water in a kettle is the conversion of **electrical energy** to **thermal energy (heat)**. The electrical energy powers the heating element in the kettle, which then transfers heat to the water, raising its temperature.<br /><br /><br />**12.**<br /><br />* **Formula:** KE = (1/2)mv²<br />* **Mass (m):** 800 kg<br />* **Velocity (v):** 15 m/s<br /><br />KE = (1/2) * 800 kg * (15 m/s)²<br />KE = (1/2) * 800 kg * 225 m²/s²<br />KE = 90000 J<br /><br />The mechanical kinetic energy of the car is 90,000 Joules.<br />