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derive relationship between commercial unit of energy and si unit of energy
if a force F is applied on a body and it moves with velocity v , the power will be :
is ncert solutions for computer science avalable
calculate the work required to be done to stop a car of 1500kg moving at a velocity of 60km/h?
1 watt of power:
If an electrical appliance is rated 1000 W and is used for 2 hours . Calculate the work done in 2 hours .
what is the relation between KW h and joules
What is the formula of sulphide ion,sulphate ion,sulphur ion ?
Q- Give one example of:-
A boy of mass 55 kg runs up a flight of 40 stairs each measuring 0.15m. Calculate the work done by the boy?
(a) Certain force acting on a 20kg mass changes its velocity from 5m /s to 2 m/s . calculate the work done by the force .
(b) State two possible condition under which the work done would be zero.
(c) if the kinetic energy of the body is increased by 300% then determine the percentage increase in the momentum.
the power of motor pump is 2kW. how much water per minute the pump can raise to a height of 10m? (given g = 10m/s)
suggest me a working science model for class 9th
The kinetic energy of an object of mass , m moving with a velocity of 5m/s is 25J.what will be its kinetic energy when its velocity is doubled ?what will be its kinetic energy when its velocity is incrased three times
A mass of 50kg is raised through a certain height by a machine whose efficiency is 90%,the energy spent is 5000J.if the mass is now released,its KE on hitting the ground shall be?
a body of mass 2 kg is thrown vertically upwards with the initial velocity of 20 m s-1. what will be its potential energy at the end of 2 seconds.(g=10m s-2)
What is the derivation of Kinetic energy and Potential energy
What is the work done to increase the velocity of a car from 30km/h to 60km/h if the mass of the car is 1500kg?
1. A block of 20 kg is pulled up by applying a force acting parallel to the slope. If the slope makes an angle of 30 degree with the horizontal, calculate the work done in pulling the load by a distance of 3m. What is the increase in potential energy of the block. (g = 10 newton per kg)
2. The speed of a bicycle decreases from 18 to 9 kmph. If the total mass of cyclist including the cycle is 70 kg, calculate the work done in overcoming the friction offered by the brakes & the road. Does the kinetic energy of the system also reduce to half its initial value?
the kE acquired by a mass m in travelling a certain distance s ,starting from rest ,under the action of a constant force is directly proportional to:
d)none of these
Q1. The volume of 50g of a substance is 20cm3 . If the denstiy of water is 1 g cm3, will the substance float or sink in water ? justify your answer ?
Q2. Show that the energy of a vibrating pendulum is conserved ?
Q3. A ball is dropped from a heigh of 10m. If the energy of the ball reduces by 40% after striking the ground, how much high can the ball bounce back ?
define 1 watt of power?
define work , its formula with SI unit ?
define power. Give the SI unit of power
renatta gass is out with her friends.misfortune occurs and renetta and her friends find themselves getting a workout.they apply a cumulative force of 1080 N to push the car 218 m to the nearest fuel station.determine the workdoneon the car.
Derive an expression for the gravitational potential energy of an object of mass 'm' at a height 'h' above the earth's surface.
A stone projected vertically upward with a velocity 'u' reaches a maximum height 'h'. Find the ratio of kinetic energy and potential energy of the stone, when it is at height 3h/4 from the ground..?
1. Can a body have energy without momentum ????
2. Can a body have momentum without energy ?????
plzz ans. with explanation ???
Identify and state the type of transformation of energy in the following cases:
1. When coal is burnt.
2. When a dry cell discharges.
3. In a thermal power plant.
A 5 kg cart is pushed by a 30 N force against friction for a distance of 10 m in 5 sec. Determine the power needed to move the cart.
Can any object have momentum even if its mechanical energy is 0? explain.
What is the work done by a satellite moving around the earth ?Justify your answer.
A freely falling object eventually stops on reaching the ground. What happens to its kinetic energy
If the speed of a body is halved ,what will be the change in its kinetic energy??????????
a man carries a suitcase in his hand and climbs up the stairs. the work done by the man is :
d) none of the above
explain also please!
why iron nail sinks and cork float on water?
give examples of the situations of work done and work not done (15-20)
I am confused as to how to find K.E. in the Activity 11.15 at Page 155 of Work and Energy chapter because we don't know the velocity in those cases. Finding P.E. is easy there. Can anybody help???
an electric heater is rated 1500w. how much energy does it use in 10 hrs.express your answer kwt and joules.
a bag of rice weighs 75 kg .calculate the height to which it should be raised so that its potential energy is 7500 j.
(given : g = 10 m/s^2)
note - the answer is 10 m.
wat is the relationship between JOULE (J) and ERG ??????
experts answer ??:DD
derive an expression for kinetic energy of a body ?
The masses of two substances are 25gm and 89gm respectively.If their kinetic energies are the same the the ratio of momentum is?
When do we say that work is done?
An object of mass of 20 kg is dropped from a height of 4 m. Fill in the blanks in the following table by computing the potential energy and kinetic energy in each case.
height at which object is located: 4 m, 3 m, 2m, 1m, just above the ground
(for simplifying the calculations, take the value of g as 10 m s-2)
can you plz give me the examples of kinetic energy?????????????
A heavy stone is lowered on the ground. The work done is positive or negative.
Explain answer briefly.
Water is falling on the Blades of a turbine at the rate of 6 * 103 kg per minure .
The height of the fall is 10 m . Claculate the power given to the turbine. Take g = 10 m/s2
what is the proof for w = F S cos theta
a truck and a car moving with same kinetic energy are stopped by applying same retarding force by means of brakes. which stops at a smaller distance?
Explain the transformation of energy in hydroelectric power plant?
define density?Give its SIunit.
a man drops 10kg rock from the top of a 5m ladder. wht is its speed just before it hits the ground? wht is its kinetic energy wen it reaches da ground.
Derive the relation between momentum and kinetic energy ??????
examples of kinetic enery and potential energy its urgent
Water stored in a dam possesses
(a) no energy (b) electrical energy (c) kinetic energy (d) potential energy
an elevator weighing 500 kg is to be lifted up at a constant velocity of 0.4m/s . what should be the minimum horse power of the motor to be used?
Derive an expression for the kinetic energy of an object of mass 'm' moving horizontally with a uniform velocity 'v'
two bodies of masses (m1) and (m2) have equal kinetic energy. what shall be the ratio of their momentum
(a) In a tug of war, one team (team A) wins and the other team (team B) loses. Which of these two teams does positive and negative work?
(b) What is the work done in case of a satellite moving around the earth?
prove that the energy remains constant in case of a freely falling body....
An electric toaster of 500 watt is switched on for 1 hour. Calculate electric energy consumed by heater.
An object of mass 40kg is raised to a height of 5m above the ground.What is its PE?If the object is allowed to fall,find its KE when it is half way downAn object of mass 40 kg is raised to a height of 5m above the ground.What is its PE?If the object is allowed to fall,find its KE when it is half way down
if you apply one joule of energy to lift a book of 0.5 kg . How high it will raise? (g= 10m/s2)
define average power
when a force retards the motion of a body
a)its kinetic energy always decreased.
b)the work done by the force is negative
c)the force acts opposite to the displacement
d)all the above
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