Advertisements
Advertisements
प्रश्न
Define work.
Define the term work
Advertisements
उत्तर
The work done by a force on a body is equal to the product of the force applied and the distance moved by the body in the direction of force i.e.,
Work done = Force × distance moved in the direction of force
APPEARS IN
संबंधित प्रश्न
When do we say that work is done?
Define 1 J of work.
An electron emitter must have _____________ work function and ___________ melting point.
A force acts on a body and displaces it by a distance S in a direction at an angle θ with the direction of the force. What should be the value of θ to get the maximum positive work?
When does a force perform work?
State the S.I. unit of work and define it.
A force of 30 N acts on a body and moves it through a distance of 5 m in the direction of force. Calculate the work done by the force.
A boy weighing 25 kgf climbs up from the first floor at height 3 m above the ground to the third floor at height 9m above the ground. What will be the increase in his gravitational potential energy? (Take g = 10 N kg -1)
Fill in the blank with suitable word :
Work is measured as a product of __________ and __________
Is it possible that a force is acting on a body but still the work done is zero? Explain giving one example.
Explain by an example that a body may possess energy even when it is not in motion.
Name five appliances or machines which use an electric motor.
Is power a scalar quantity?
A 100 W electric lamp emits energy in the form of light at the rate 10 J per second. What percentage of electric energy does the lamp transform into light energy?
A woman pulls a bucket of water of total mass 5 kg from a well which is 10 s. calculate the power used by her.
Name the CGS unit of work.
How fast should a boy weighting 30 kg run so that his kinetic energy is 375 joule?
State the energy changes which take place when Water stored in the dam is used to turn turbine in dynamo.
What do you understand by the term energy? Is energy a scalar or vector? How is the energy possessed by a body measured?
Explain, why submarines are able to dive underwater as well as a sail on the surface of the water?
A truck driver can load oil drums into the back of the truck by pushing them up a sloping plank, or by lifting them directly. Each drum has a mass of 80 kg, the plank is 3 m long, and the back of the truck is 0.8 m above the ground.
(i) How much force would be needed to lift a drum into the truck directly/without using the plank? (Take g = 10 m/s2)
(ii) How much energy would be required in lifting the drum into the truck without the plank?
(iii) If the force needed to push the drum up the plank is 300 N, why is this less than the answer to part (i)?
(iv) When the truck is loaded, the driver drives off. List the major energy changes that take place in moving the truck.
(v) The driver has to stop at the factory gates. What happens to the kinetic energy of the truck?
An electric motor of power 100 W is used to drive the stirrer in a water bath. If 50% of the energy supplied to the motor is spent in stirring the water. Calculate the work done on the water in one minute.
A car is accelerated on a levelled road and attains a velocity 4 times of its initial velocity. In this process the potential energy of the car
