Select Board & Class
derive relationship between commercial unit of energy and si unit of energy
is ncert solutions for computer science avalable
if a force F is applied on a body and it moves with velocity v , the power will be :
calculate the work required to be done to stop a car of 1500kg moving at a velocity of 60km/h?
name the transformation of energy involved in the following cases :
1) when a body is throw upwards.
2) when a body falls from the top of a hill
3) when coal burns
4) when a gas burns
5) when water falls from a height
1 watt of power:
what is the relation between KW h and joules
a body performs no work. Does it implies the body possesses no energy.
What is the formula of sulphide ion,sulphate ion,sulphur ion ?
A heavy stone is lowered on the ground. The work done is positive or negative.
Explain answer briefly.
Q- Give one example of:-
A 2m high person is holding a 25kg trunk on his head and is standing at a roadways bus- terminus. how much work is done by the person ?
(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.
calculate the energy possessed by a stone of mass 10 kg kept on a height of 5m(g = 9.8)
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
what will be the kineic energy of a body when its mass is made 4 times and velocity is doubled?
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
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 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?
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
A coolie carries a load of 50kg on his head and walks on a level road up to 100m. what is the work done by him.
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 boy of mass 55 kg runs up a flight of 40 stairs each measuring 0.15m. Calculate the work done by the boy?
define 1 watt of power?
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)
define work , its formula with SI unit ?
define power. Give the SI unit of power
state & explain the law of conservation of energy with an example 2. explain how total energy a swinging pendulam at any instant of time remains conserved illustrate your answer with the help of Lbelled diagram
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..?
In an oscillating pendulum, at what positions the potential and kinetic energy are maximum?
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.
A student is writing Three hour science paper how much work is done by a student ? Give reason for your answer .
What is the work done by a satellite moving around the earth ?Justify your answer.
when a book is lifted from a table , against which force work is done ?
A freely falling object eventually stops on reaching the ground. What happens to its kinetic energy
Two objects of unequal mass are dropped from a cliff. At any instant they have equal
a) Momentum b) Acceleration c) Potential energy d) Kinetic energy
If the speed of a body is halved ,what will be the change in its kinetic energy??????????
why iron nail sinks and cork float on water?
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???
give examples of the situations of work done and work not done (15-20)
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 ??:DD
Two bodies of different masses m1 and m2 (m1>m2) have same kinetic energy . They are stopped by applying some retarding force . Which body will stop first ?
derive an expression for kinetic energy of a body ?
calculate the electrical energy consumed in joules if a toaster of 60W is used for 30 minutes
When do we say that work is done?
7. If a man lifts a load up with the help of a rope such that it raises the load of mass 50kg
to a height of 20m in 100 sec. Find the power of man
8. A ball is dropped from a height of 5m. Find the velocity of the ball just before it
reaches the ground. Do you require the value of mass to find the velocity?
9. Two persons A and B do same amount of work. The person A does that work in t1sec
and the person b in t2sec. Find the ratio of power delivered by them.
can you plz give me the examples of kinetic energy?????????????
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?
define density?Give its SIunit.
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.
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 ??????
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
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
1. State the energy changes taking place in the following cases: (1) A car moves up a
Derive an expression for the kinetic energy of an object of mass 'm' moving horizontally with a uniform velocity 'v'
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
two bodies of masses (m1) and (m2) have equal kinetic energy. what shall be the ratio of their momentum
prove that the energy remains constant in case of a freely falling body....
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
1. Derive the formula for work done by a constant force?
define average power
Explain the transformation of energy in hydroelectric power plant?
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