Work and Energy in Physics

The video tutorial explains the concept of work in physics, where work is done when a force moves an object, transferring energy to it. The formula for work is given as W = F × D, where W is work, F is force, and D is distance. An example is provided with a lady pushing a trolley, calculating the work done and the resulting kinetic energy. The tutorial further explains how to calculate the velocity of the trolley using its kinetic energy and mass.

In physics, when is work said to be done?

• When energy is lost.

• When time passes.

• When a force moves an object.

• When an object is stationary.

What is the formula for calculating work done?

• W = D - F

• W = F + D

• W = F * D

• W = F / D

In the example of the lady pushing a trolley, what is the force applied?

• 200 Newtons

• 100 Newtons

• 50 Newtons

• 150 Newtons

How much work is done when a force of 100 Newtons is applied over 15 meters?

• 150 Joules

• 1500 Joules

• 2000 Joules

• 1000 Joules

What is the unit of work in physics?

• Newton

• Watt

• Pascal

• Joule

What type of energy is transferred to the trolley in the example?

• Potential energy

• Thermal energy

• Chemical energy

• Kinetic energy

What is the formula for kinetic energy?

• KE = 1/2 mv

• KE = mgh

• KE = mv

• KE = 1/2 mv^2

If a trolley has a mass of 50 kg and gains 1500 Joules of kinetic energy, what is its velocity squared?

• 30

• 60

• 90

• 120

What is the final velocity of the trolley after being pushed?

• 5.5 m/s

• 7.7 m/s

• 8.8 m/s

• 6.6 m/s

What is the mass of the trolley in the example?

• 40 kg

• 60 kg

• 30 kg

• 50 kg