Work, power And Kinetic Energy

Question 1

What is the formula for kinetic energy?

Answer 1

Kinetic energy (Ek) = 1/2 mv²

Where m is mass and v is velocity.

Question 2

How much kinetic energy does a 25 kg ball moving at 2 m/s have?

Answer 2

5 Joules

Calculated using the formula for kinetic energy.

Question 3

If a marble is thrown with a velocity of 3 m/s, what is the kinetic energy if its mass is 0.09 kg?

Answer 3

0.405 Joules

Calculated using the kinetic energy formula.

Question 4

What does power measure in physics?

Answer 4

The amount of energy transferred per second

Power (P) = Work done (J) / Time (s).

Question 5

What is the unit of power?

Answer 5

Watts (W)

1 Watt = 1 Joule/second.

Question 6

How is power calculated?

Answer 6

Power (P) = Work done (J) / Time (s)

Rearranges to find work done: Work done = Power x Time.

Question 7

What is the power of a person weighing 480 N climbing stairs of height 10 m in 12 s?

Answer 7

400 Watts

Power calculated as P = Work done / Time.

Question 8

How much work is done when a box is pushed 5 m against a friction force of 60 N?

Answer 8

300 Joules

Work done (WD) = Force x Distance.

Question 9

Fill in the blank: Work done = _______ x Distance.

Answer 9

Force

This is the fundamental equation for calculating work done.

Question 10

What is the total work done by a person climbing 6.5 m up a ladder with a mass of 60 kg?

Answer 10

5200 Joules

Weight = mass x gravity.

Question 11

True or False: Power is the same as work done.

Answer 11

False

Power is the rate of doing work, not work itself.

Question 12

What is the formula for gravitational potential energy?

Answer 12

Potential Energy (PE) = mass x gravity x height

Commonly used to calculate energy in vertical movements.

Question 13

Calculate the work done if a tractor pulls a plough 60 m doing 12,000,000 J of work.

Answer 13

The frictional force can be calculated as 200,000 N

Using the formula: Work done = Force x Distance.

Question 14

How much energy does a 1.2 kW motor transfer if it is used for 3 minutes?

Answer 14

216,000 Joules

Energy = Power x Time.

Question 15

What is the mean power required for an athlete performing 50 press-ups per minute for 6 minutes, raising his center of mass 24 cm?

Answer 15

64,800 Watts

Total work done calculated from the distance raised and mass.

Question 16

Fill in the blank: The equation for Work Done is _______ x Distance.

Answer 16

Force

This indicates that work is dependent on both the force applied and the distance moved.