Power - AP Physics 1

1. State the unit of power in the International System of Units (SI).

   Watt (W). Named after James Watt, equal to one joule per second.

2. Calculate the power if the force is 10 N and the velocity is 5 m/s.

   50 W. Apply $P = F \times v = 10 \times 5$.

3. Which physical quantity is the rate of doing work?

   Power. Power measures how quickly work is performed.

4. What is the formula for mechanical power in terms of work and time?

   $P = \frac{W}{t}$. Work per unit time defines mechanical power.

5. What is the equivalent of 1 horsepower in watts?

   746 W. Historical unit conversion for mechanical power.

6. What is the formula for power in terms of torque and angular velocity?

   $P = \tau \times \frac{d\theta}{dt}$. Rotational power equals torque times angular velocity.

7. State the formula for power in terms of energy and time.

   $P = \frac{E}{t}$. Energy transferred per unit time defines power.

8. What is the formula for instantaneous power using force and velocity vectors?

   $P = \textbf{F} \bullet \textbf{v}$. Dot product accounts for force direction relative to velocity.

9. Determine the power if a device uses 150 J of energy in 3 seconds.

   50 W. Apply $P = \frac{E}{t} = \frac{150}{3}$.

10. What is the formula for power in terms of mass, gravity, height, and time?

    $P = \frac{mgh}{t}$. Power to lift mass against gravity over time.

11. Calculate the power if a force of 10 N moves a body at 3 m/s.

    30 W. Use $P = F \times v = 10 \times 3$.

12. Calculate the power if a machine does 800 J of work in 4 seconds.

    200 W. Use $P = \frac{W}{t} = \frac{800}{4}$.

13. Calculate the power of a machine that does 200 J of work in 10 seconds.

    20 W. Use $P = \frac{W}{t} = \frac{200}{10}$.

14. What is the formula for power in terms of energy change and time?

    $P = \frac{\triangle E}{t}$. Change in energy over time interval.

15. Identify the power if 500 J of work is done in 5 seconds.

    100 W. Apply $P = \frac{W}{t} = \frac{500}{5}$.

16. Identify the power if 1 kWh of energy is consumed in 1 hour.

    1000 W. One kilowatt-hour consumed in one hour.

17. Identify the power if 50 J of work is done in 5 seconds.

    10 W. Apply $P = \frac{W}{t} = \frac{50}{5}$.

18. What is the definition of power in physics?

    Rate of doing work or transferring energy. Fundamental definition in terms of work and energy.

19. What is the formula for power in terms of force and velocity?

    $P = F \times v$. Force dot product with velocity gives instantaneous power.

20. Identify the formula for power in rotational motion.

    $P = \tau \times \frac{d\theta}{dt}$. Torque times instantaneous angular velocity.

21. What is the formula for power using force, displacement, and time?

    $P = \frac{F \times d}{t}$. Force times displacement per unit time equals power.

22. Calculate the power if energy of 240 J is used in 4 seconds.

    60 W. Apply $P = \frac{E}{t} = \frac{240}{4}$.

23. Determine the power if a light bulb uses 60 J of energy in 1 second.

    60 W. Energy consumption rate equals 60 joules per second.

24. Identify the power output for a motor that does 4000 J of work in 20 seconds.

    200 W. Apply $P = \frac{W}{t} = \frac{4000}{20}$.

25. Identify the unit equivalent to one watt in terms of basic SI units.

    1 W = 1 J/s. One watt equals one joule of energy per second.

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