Work and energy, Physics

Assignment Help:

WORK AND ENERGY

 

1.  Work can be defined as: the force applied in direction of displacement ×.  This means that if the force F acts at an angle θ with respect to the direction of motion, then 

      →   →

W = F ⋅ d = Fd cosθ

1233_work energy.png

2.  a) Work is the scalar quantity - it has magnitude but no direction.

b) The dimensions of the  work are: M × (L T -2 ) × =  M L2T -2

 

c) The units: 1 Newton × 1 Metre =  1 Joule (J)

 

3.  Suppose you lift the mass of 20 kg from a distance of 2 metres. Afterwards the work you perform is 20 kg × 9.8 Newtons × 2 metres  = 39.2 Joules. Conversely, the force of gravity is directed opposite to the force exerted by you and the work done by gravity is - 39.2 Joules.

 

4. What if the force differs with distance (as we pull the spring harder as it becomes longer). In such case, we should break up distance over which the force acts into small parts so that the force is approximately constant over each bit. As we create the pieces smaller and smaller, we will attain the exact result:

0

90_work energy2.png

Now add up all the little pieces of work:

1863_work energy1.png

To get the exact result let Δx → 0 and the number of intervals N

7.  Energy is the capacity of a physical system to perform work:

?    it comes in various forms - mechanical, nuclear, chemical, electrical,  etc

1)   it can be stored

2)   it can be converted into different forms

3)    it can never be created or destroyed


Related Discussions:- Work and energy

What would then be the sun''s new rotation period, Suppose that the Sun run...

Suppose that the Sun runs out of nuclear fuel and suddenly collapses to form a white dwarf star, with a diameter equal to that of the Earth. Assuming no mass loss, what would then

Optic fiber, why the reflective index of cladding is lower then in core of ...

why the reflective index of cladding is lower then in core of a fiber optic?

What are basic attenuation mechanisms in a fibre, What are basic attenuatio...

What are basic attenuation mechanisms in a fibre? The fundamental attenuation mechanisms into a fibre are as follows: a. Absorption b. Scattering (Mie and Rayleigh scatte

Astrophysics question, consider a star orbitining in the sperically graviat...

consider a star orbitining in the sperically graviational potential Y=(Vc)2 ln(r/r0). a)use conservation of energy and angular momentum to obtain equation for dr/dt and d(teta)/dt

Cosmic censorship conjecture, Cosmic censorship conjecture (R. Penrose, 197...

Cosmic censorship conjecture (R. Penrose, 1979) The conjecture, so far completely undemonstrated in the context of general relativity, that all singularities (along the possib

Electronics, list the factors used to classify inductors.

list the factors used to classify inductors.

Electrostatics, What is quantisation of electric charge?

What is quantisation of electric charge?

State the process of diffusion, State the process of diffusion When  th...

State the process of diffusion When  these  two  pieces  are  joined  together and  suitably  treated,  they  from  a  pn junction. Moment they form a pn junction, some of the

Bernoullis theorem, what is the theory behind bernoullies theorem?

what is the theory behind bernoullies theorem?

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd