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Syeda answered 1 year(s) , 10 month(s) ago

Derive the expression kinetic energy, potential energy

Derivation for the equation of Potenstial Energy:
Let the work done on the object against gravity = W
Work done, W = force × displacement...

Dec 24

• 7 Likes
• 67769 Views

Dec 24

Fibin answered 4 year(s) ago

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

m=1500kg

u= 60km/h =60* 5/18 = 50/3m/s

v =0m/s

w = change in its KE.

initial KE =1/2 mu 2

final KE=1/2mv²
...

Feb 6

• 2 Likes
• 40774 Views

Feb 6

Ravinder answered 5 year(s) , 1 month(s) ago

Derivation of the equation for kinetic energy (K.E = ½ m v 2)

Expression for  Kinetic energy(E k )-
Consider an object with mass m, moving with initial velocity u. Let a force F, act on it causing a displacement s, along the direction of force and acce...

Mar 12

• 4 Likes
• 25136 Views

Mar 12

Janhavi answered 4 year(s) , 1 month(s) ago

An electric bulb of 60W is used for 6 hours per day calculate the units of energy consumed in one day by the bulb.

Electrical energy consumed by the bulb per day = P x t = 60 W x 6h = 360 Wh

1 unit = 1 kW h = 1000 W h
1 W h = (1/1000) unit
360 W h = 0.360 unit
Electrical energy consum...

Mar 4

• 4 Likes
• 20049 Views

Mar 4

Janhavi answered 4 year(s) , 1 month(s) ago

1. What is work done by a coolie walking on level road with load on his head? 2. Why is work done zero when, the direction of displacement and the direction of force on a body are perpendicular to each other?

1. Work done by a coolie, walking  on level road with load on his head,  on the load is zero.
2. Work done = Force x displacement

W = F.s = Fs cos θ

where  θ is the angle be...

Feb 17

• 2 Likes
• 18585 Views

Feb 17

Syeda answered 1 year(s) , 10 month(s) ago

what are three characteristics of sound waves ? On what factors do they depend .

i) Pitch depends on the frequency of the sound waves produced by the source.

(ii) Quality (or Timbre) of the sound depends on wave form....

Jan 2

• 2 Likes
• 17036 Views

Jan 2

Syeda answered 2 year(s) , 2 month(s) ago

commercial unit of energy

Commercial Unit of Energy. The SI unit joule is too small to express very large quantities of energy. Hence we use a bigger unit called kilowatt hour (kWh) to express energy. 1 kWh is th...

Feb 18

• 3 Likes
• 15309 Views

Feb 18

Rahul answered 3 year(s) , 1 month(s) ago

Is Potential energy a vector quantity or scalar?

Its a scalar quantity

Oct 14

• 3 Likes
• 14086 Views

Oct 14

Syeda answered 1 year(s) , 10 month(s) ago

State the factors on which work done depends?

1) a force is applied on the object

2)there is a displacement in the direction of the force of the object

Mar 15

• 1 Like
• 13771 Views

Mar 15

Garvita commented 4 year(s) , 3 month(s) ago

A body of mass 2 kg falls from rest. What will be its kinetic energy during the fall at the end of 2 s?(assume g=10.)

Mass of the body m = 2 kg
Initial speed u = 0
t = 2 s
g = 10 m/s 2.
For a freely falling body the final velocity at the end of t s is given by
v = u + gt = 0...

Jan 5

• 0 Like
• 13448 Views

Jan 5

Janhavi answered 4 year(s) ago

A force is applied on a car of mass 1500 kg, so that its speed increases from 54 km/h to 72 km/h. Find the work done by the force on the car.

Mass of car m = 1500 kg
Initial velocity = 54 km/h = 54 x 5/18 = 15 m/s
Final velocity = 72 km/h = 72 x 5/18 = 20 m/s
( 1 km/h = 1000 m/ (3600 s) = 5/18 m/s
Initial kinetic ener...

Mar 16

• 2 Likes
• 12675 Views

Mar 16

Amarnathreddy answered 5 year(s) , 2 month(s) ago

Deriva a relation between momentum and kinetic energy

Feb 8

• 1 Like
• 11356 Views

Feb 8

Amarnathreddy answered 4 year(s) , 3 month(s) ago

Derive the formula for work done by a constant force.

Let the initial velocity = u,
Final velocity = v,
Uniform acceleration = a, and
Displacement = S, then

v 2 - u 2 = 2aS This gives  ...

Jan 11

• 1 Like
• 9308 Views

Jan 11

Janhavi answered 4 year(s) , 2 month(s) ago

A porter lifts a luggage of 15 kg from the ground and put it on his head 1.5 m above the ground . Calculate the work done by him on the luggage.

Work done by the porter on the luggage = Force x displacement
= mgh
...

Jan 14

• 2 Likes
• 8758 Views

Jan 14

Amarnathreddy answered 5 year(s) , 3 month(s) ago

can any object have Mechanical energy if its momentum is 0? explain.

Can any object have Mechanical energy if its momentum is 0? Explain.
Answer:  Momentum is the product of mass and velocity of a body, for a body mass never be zero but...

Jan 14

• 0 Like
• 8301 Views

Jan 14

Janhavi answered 4 year(s) , 1 month(s) ago

Water is falling on the blades of a turbine at the rate of 8 x 102 kg per minute, height of fall is 50 m, calculate the power given to turbine. (g=10 m/s2)

Power = Work done/time
= mgh/t
= (8 x 10 2/60)(kg/s) x (10 m/s 2) x 50 m
= 6666.6 W
= 6.6666 kW

Mar 8

• 2 Likes
• 7394 Views

Mar 8

Agam answered 11 month(s) , 27 day(s) ago

A truck of mass 1800 kg is moving witha speed 54 km/h when brakes are appiled it stops with uniform retardation at a distance of 200 m.Calculate the force appiled by the brakes of the truck and the work done before stopping.

Mass of the truck m = 1800 kg
Initial speed u = 54 km/h = 15 m/s
Final speed v = 0
s = 200 m
We have v 2 - u 2 = 2as
a = (v 2 - u 2 )/(2s)
= (0 - 15 2 )/400 =...

Mar 1

• 1 Like
• 6857 Views

Mar 1

Janhavi answered 4 year(s) , 6 month(s) ago

Are various energy forms interconvertible?

Yes, various forms of energy are interconvertible. Look at the following examples.

• Sound energy is converted into electrical energy in a microphone.
• Electrical energy is converted into so
...

Oct 11

• 0 Like
• 6165 Views

Oct 11

Amarnathreddy answered 4 year(s) , 1 month(s) ago

What is meant by average power?

Average power the ratio of the total work done by the body and the total time taken.
Power = Energy consumed/ Time taken = work done / Time

Mar 10

• 3 Likes
• 6137 Views

Mar 10

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