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derive relationship between commercial unit of energy and si unit of energy
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
is ncert solutions for computer science avalable
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..?
calculate the work required to be done to stop a car of 1500kg moving at a velocity of 60km/h?
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 watt of power:
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) 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 kinetic energy acquired by a body of mass m after travelling a fixed distance from rest under the action of a constant force is
a) directly proportional to mass m
b)inversely proportional to mass m
c) inversely proportional to mass m to the power 12
d) independent of mass m
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
A body starts from rest and acquires a velocity V in time T. The work done on the body in time t is proportional toA) Vt/tB) Vsquare tsquare/ TC)Vsquare tsquare/ T
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)
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?
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 block of mass 1 kg slides down on an inclined plane of inclination 30 degrees.Calculate the work done by the bklocks weight as it slides through 50 cm.
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?
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:
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 ?
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
define 1 watt of power?
define work , its formula with SI unit ?
An object of mass 10 kg falls from rest through a vertical distance of 10m and acquires a velocity of 10m/s . The work done by the push of air on the object is (g=10 m/s 2 )
a) 500J b)-500J c)250J d)-250J
define power. Give the SI unit of power
Derive an expression for the gravitational potential energy of an object of mass 'm' at a height 'h' above the earth's surface.
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.
Can any object have momentum even if its mechanical energy is 0? explain.
Calculate the work done in raising a stone of mass 5 kg and specific gravity 3 lying at the bed of a lake through a height of 5 metre.
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
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:
why iron nail sinks and cork float on water?
wat is the relationship between JOULE (J) and ERG ??????
experts answer ??:DD
an electric heater is rated 1500w. how much energy does it use in 10 hrs.express your answer kwt and joules.
A diwali rocket is ejecting 0.05 kg of gases per second at a velocity of 400 m s -1 . The accelerating force on the rocket is
( a ) 20 dyne ( b ) 20 newton
( c ) 20 kg wt ( d ) sufficient data not given
If the speed of a body is halved ,what will be the change in its kinetic energy??????????
derive an expression for kinetic energy of a body ?
two bodies of mass 1kg and 4kg have equal kinetic energy.wat is the ratio of their momentum?
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???
When do we say that work is done?
can you plz give me the examples of kinetic energy?????????????
A bread gives a boy of mass 40kg of energy 21KJ.If the efficiency is 28% the the height can be climbed by using this energy is:
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
a body falls freely under gravity . its velocity is v when it has lost potential energy equal to U. what is the mass of the body?
define density?Give its SIunit.
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)
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?
what is the proof for w = F S cos theta
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.
two bodies of masses m1 and m2 have equal kinetic energies . If P1 and P2 are their respective momentum , then ratio P1: P2 is ...............plz give in Detail step by step
examples of kinetic enery and potential energy its urgent
2. A car is accelerated on a levelled road and attains a velocity 4 times of its
Derive the relation between momentum and kinetic energy ??????
A quarter horse power motor runs at a speed of 600 r.p.m. Assuming 40% efficiency, then what will be the work done by the motor in one rotation?
Derive an expression for the kinetic energy of an object of mass 'm' moving horizontally with a uniform velocity 'v'
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
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/s2)
a)550J b)525 J c)125J d)500J
Water stored in a dam possesses
(a) no energy (b) electrical energy (c) kinetic energy (d) potential energy
A block of mass 2 kg is lying on the frictionless table. A force of 8N is applied on it for 12 seconds. Calculate its Kinetic Energy.
define average power
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
prove that the energy remains constant in case of a freely falling body....
Prove law of conservation of energy for an object thrown vertically upward .
Explain the transformation of energy in hydroelectric power plant?
A bullet is fired normally on an immovable plank of wood. It loses 25% of its kinetic energy in penetrating a thicknees x of the plank. What is the total thickness penetrated by the bullet?
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