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derive relationship between commercial unit of energy and si unit of energy

is ncert solutions for computer science avalable

The kinetic energy of a car is 7000 J as it travels along a horizontal road. How much work is required to stop the car in 20 s?

calculate the work required to be done to stop a car of 1500kg moving at a velocity of 60km/h?

the k

_{E }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:a)

mb)/

mc)1//

md)none of theseDefine 1 watt of power:a 2-kg body is sliding up an inclined plane of inclination 30degree .find the work done by the force of gravity in moving the body through 1m.

what is the relation between KW h and joules

^{2})Ans.- 20*10

^{-4}approx.)2.A boy of mass 50 kg sits on the swing, suspended by a rope 5 m long. A person pulls the rope that makes the angle of 30

^{0}with the vertical. What is the gain in the gravitational potential energy of the boy?(Ans.- 328.3 J)

3. The brakes of an unloaded lorry of mass 1000 kg will slow it down from 40 to 20 km/h in 7.5 s. How long will they take to stop it from a speed of 30 km/h, if it has taken on a load of 2200 kg?

(Ans.- 36s )

4. The propelling force of a rocket increases uniformly from zero to 5 N in the first 12 m and remains constant for the next 40 m. Find the total work done.

(Ans.- 2300 J)

4. The potential energy stored in the wound up spring of a toy motor-car is 18 J. Ignoring any frictional resistance to motion , find the distance this car (mass 200g ) will travel up a slope of 1 in 5.

(Ans.- 45.9 cm )

What is the formula of sulphide ion,sulphate ion,sulphur ion ?

A person draws water from a5m deep well in a bucket of mass 2 kg of capacity 8 litre by a rope of mass 1kg. what is the total work done by the person?(assume g= 10 m/s

^{2}^{)}^{a)550J b)525 J c)125J d)500J}Q- Give one example of:-

If the speed of a body is halved ,what will be the change in its kinetic energy??????????

plz answer

(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.

Body of mass 5kg is moving with a velocity 10m/s . Find its kinetic energy. Find the ratio of initial kinetic energy and final kinetic energy if (a) mass is doubled (b) it's velocity is made three times

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)

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

Potential energy

Kinetic energy

(for simplifying the calculations, take the value of g as 10 m s

^{-2})suggest me a working science model for class 9th

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})Compare the kinetic energies of 2 objects of masses 10 kg and 50 kg respectively but having same momentum

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

What is the derivation of Kinetic energy and Potential energy

if the heart of a man pumps 4 litres of blood per minute at a pressure of 130 mm of mercury

if the density of mercury is 13.6 gcm-3 calculate the power of heart

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?

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 ?

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..?

define 1 watt of power?

A student is writing Three hour science paper how much work is done by a student ? Give reason for your answer .

define work , its formula with SI unit ?

Find the change in momentum of a body when its kinetic energy becomes four times the original value.define power. Give the SI unit of power

Force acting on a particle moving in a straight line varies with the velocity of the particle as F=k/v,where K is a constant.The work done by this force in time t is:

(A)K/v^2.t

(B)2Kt

(C)Kt

(D)2Kt/v^2

Derive an expression for the gravitational potential energy of an object of mass 'm' at a height 'h' above the earth's surface.

what is the proof for w = F S cos theta

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.

calculate he relative molecular mass of water(H

_{2}O)....?Can any object have momentum even if its mechanical energy is 0? explain.

An engine pulls a car of mass 1500kg on a level road at constant speed of 5m/s.If the frictional force is 500N,what power does the engine generate?

1. Can a body have energy without momentum ????

2. Can a body have momentum without energy ?????

plzz ans. with explanation ???

Define 1J of Work?

What is the work done by a satellite moving around the earth ?Justify your answer.

a force of 5N is acting on an object. the object is displaced through 2m in the direction. if the force acts on the object all through the displacement, then work is 5N multiply by 2m =10N m or 10j

A freely falling object eventually stops on reaching the ground. What happens to its kinetic energy

why iron nail sinks and cork float on water?

a) E1=(m2/M)E

B) E1= m1/m2? E

C) E1= m1/M? E

D) E1= m2/m1? E

^{o}^{ }with the horizontal. Then, what will be the work done by the force of gravity ? (Ans: 86.6 J)Please find the solution.

an electric heater is rated 1500w. how much energy does it use in 10 hrs.express your answer kwt and joules.

wat is the relationship between JOULE (J) and ERG ??????experts answer ??:DDI 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???

Write the various energy transformations that occur in the following cases.

derive an expression for kinetic energy of a body ?

State the relation between commercial unit of energy and joules .!How much work is done on a body of mass 1kg whirling on a path of radius 5m ?If an object is immersed wholly in a liquid causing upthrust equal to the weight of the body then what will be the relation between the relative densities of liquid and the object ?In a house 3 bulbs of 25 W each are used for 5 hours a day . Calculate the units of electricity consumed in a month of 31 days . Also find the total expenditure if 1 unit of electricity costs Rs 2.50.

When do we say that work is done?

can you plz give me the examples of kinetic energy?????????????

^{2}.What would have happened if nature had not allowed the transformation of energy?

Water is falling on the Blades of a turbine at the rate of 6 * 10

^{3 kg per minure .}The height of the fall is 10 m . Claculate the power given to the turbine. Take g = 10 m/s

^{2}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?

A car weighing 1200 kg is uniformly accelerated from rest and covers a distace of 40m in 5 sec. calculate the work done by car engine

define density?Give its SIunit.

why does air move from place to place?

calculate the electricity bill amount for a month of 30 days if 4 bulbs of 50 W for 6 hrs ,3 tubelights of 40 W for 3 hrs, a TV of 100 W for 6 hrs,a refrigerator of 300 W for 24 hrs are used.The cost per unit is Rs.2.50

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

A ball of mass 5kg is dropped from a tower of height 2 meters. what is its kinetic energy half way down?

please give the answer before 29/11/2013.

Derive an expression for the kinetic energy of an object of mass 'm' moving horizontally with a uniform velocity 'v'

Water stored in a dam possesses

(a) no energy (b) electrical energy (c) kinetic energy (d) potential energy

The propelling force of a rocket increases uniformly from zero to 5N in the first 12m and remains constant for the next 40 m. Find the total work done

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

define average power

two bodies of masses (m1) and (m2) have equal kinetic energy. what shall be the ratio of their momentum

Illustrate the law of conservation of energy by discussing the energy changes which occur when we draw a pendulum bob to one side and allow it to oscillate. Why does the bob eventually come to rest? What happens to its energy eventually? Is it a violation of the law of conservation of energy?

A 1000 kg elevator rises from rest in the basement to the fourth floor,a distance of 20m.As it passes the fourth floor its speed is 4m/s. There is a constant frictional force of 500N. The work done by the lifting mechanism is:

(A)196*10^3 J

(B)204*10^3 J

(C)214*10^3 J

(D)203*10^5 J

prove that the energy remains constant in case of a freely falling body....

1. Derive the formula for work done by a constant force?