Select Board & Class
derive relationship between commercial unit of energy and si unit of energy
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?
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
1 watt of power:
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
what is the relation between KW h and joules
a 1000 w oven is used everyday for 90 min . calculate the unit of electrical energy oven consumed in 30 days
What is the formula of sulphide ion,sulphate ion,sulphur ion ?
The potential energy of a freely falling object decreases progressively. What happens to its (i) kinetic energy (ii) total mechanical energy? State the law on which your answer is based.
A household consumes 1 kWh of energy per day. How much energy is this in joule?
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.
1. Can a body have energy without momentum ????
2. Can a body have momentum without energy ?????
plzz ans. with explanation ???
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)
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 ?
suggest me a working science model for class 9th
a burner consumes 110 kj of energy in 55 seconds .what is the power of the burner in kilowatt ?
(note - the answer is : 2 kw ).
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
In an oscillating pendulum, at what positions the potential and kinetic energy are maximum?
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)
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.
What is the derivation of Kinetic energy and Potential energy
what is the proof for w = F S cos theta
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
if a force F is applied on a body and it moves with velocity v , the power will be :
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 an electrical appliance is rated 1000 W and is used for 2 hours . Calculate the work done in 2 hours .
define 1 watt of power?
define work , its formula with SI unit ?
A 40 kg girl is running along a circular path of radius 1 m with a uniform speed. How much work is done by the girl in completing one circle?
define power. Give the SI unit of power
name the physical quantity defined by rate of doing work. define its S.I unit
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..?
Name the devices or machines which convert (1) Chemical Energy into Heat Energy (2) Light Energy into Heat Energy (3) Heat Energy into Kinetic Energy. What must be the power of the brakes of a car for them to stop the car moving at a velocity of 60 km per hour , weighing 1500 kg?
two balls have different masses but same kinetic energy.which has more momentum??/?
justify your answer.
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.
What would have happened if nature had not allowed the transformation of energy?
Can any object have momentum even if its mechanical energy is 0? explain.
Please help me to answer this activity:
What is the work done by a satellite moving around the earth ?Justify your answer.
give examples of the situations of work done and work not done (15-20)
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??????????
why iron nail sinks and cork float on water?
velocity of a body is increased by 5 times what happens to its kinetic energy?
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???
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.
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
Which of the following is carried by the waves from one place to another:
a) mass b) velocity c) wavelenght d) energy
derive an expression for kinetic energy of a body ?
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:
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?????????????
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 ?
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 1000 watt electric oven is used everyday for 90 minutes . calculate the units of electrical energy , this oven will consume in 30 days of use.
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.
why is the concept of average power useful?
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
a rectangular pit with an area A at its base and depth H is filled with water.a pump forces the water onto the surface through a cylindrical pipe of radius R. what work is done by the pump if it pumps out all the water during the time T.(density of water is =d)
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
prove that the energy remains constant in case of a freely falling body....
A man of mass 50kg runs up a flight of stairs having a rise of 5m, is 4s.
1.what is work done?
2.what is average power developed by man?
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
Explain the transformation of energy in hydroelectric power plant?
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