Expression for Kinetic Energy
Expression for Kinetic Energy
Kinetic Energy: The energy of an object because of its motion is called its kinetic energy. Its SI unit is Joule (J). A flying bird, a running man, a moving train and a swinging bat are some examples of bodies with kinetic energy. Kinetic energy of a body moving with certain velocity is equal to the work done on it to make it acquire that velocity. Kinetic energy of an object increases with its speed.
· Due to kinetic energy, a bullet fired from a gun can pierce a target.
· A moving hammer, drives a nail into a wooden block. Due to its motion, it has kinetic energy or ability to do work.
The kinetic energy of a body of mass m moving with a velocity v is
Sometimes, a large rock from space hits the earth’s surface at a very high speed. Its huge kinetic energy creates a large crater on the earth’s surface. One such crater was formed thousands of years ago at Lonar in Maharashtra. The diameter of this crater is 1.8 km.
Expression for Kinetic Energy: Suppose a body of mass “m” moving with a uniform velocity “u”. Force “F” starts acting on it in the horizontal direction and displaces it through a distance of “s” and it attains a velocity “v”. Then, work done to increases its velocity from “u” to “v”.
According to equation of motion:
So, as the object starts from rest and distance travelled is x
(1)
According to the definition of Force
F = ma
Or
Putting the value of a in the Equation (1), we get
But Fx is the work done by the force on the body. It should be equal to the increase in the kinetic energy of the body as it moves from A to B. Also, since the kinetic energy at A was zero, the increase in kinetic energy should be equal to the kinetic energy at B. So, we conclude the following:
The kinetic energy of a body of mass m moving with a speed v is
Example:Find the kinetic energy of a ball of mass 200 g moving at a speed of 20 cm/s.
Solution The kinetic energy is
Given m= 200g = 0.2 Kg
v = 20 cm/s = 0.2m/s
Q. If a stone of mass 3 kg be thrown with a kinetic energy of 37.5 J, find its velocity.
Solution: Here, mass m = 3 kg, K.E. = 37.5 J, velosity of stone, v = ?
From
Kinetic energy possessed by a car, moving at a speed of 5 m/sec is 5000 J. The mass of the car is
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| Right Option : A | |||
| View Explanation | |||
Two bullets P and Q, masses 10g and 20g, are moving in the same direction towards a target with velocities of 20 m/s and 10 m/s respectively. Which one of the bullets will pierce a greater distance through the target ? | |||
| Right Option : A | |||
| View Explanation | |||
The kinetic energy of a body will becomes eight times if - | |||
| Right Option : C | |||
| View Explanation | |||
Students / Parents Reviews [20]
Third consective year,my ward is in Abhyas with nice experience of admin and transport support.Educational standard of the institute recumbent at satisfactory level. One thing would live to bring in notice that last year study books was distributed after half of the session was over,though study ...
Ayan Ghosh
8thThe experience was nice. I studied here for three years and saw a tremendous change in myself. I started liking subjects like English and SST which earlier I ran from. Extra knowledge gave me confidence to overcome competitive exams. One of the best institutes for secondary education.
Aman Kumar Shrivastava
10thAbhyas is good institution and a innovative institute also. It is a good platform of beginners.Due to Abhyas,he has got knoweledge about reasoning and confidence.My son has improved his vocabulary because of Abhyas.Teacher have very friendly atmosphere also.
Manish Kumar
10thMy experience was very good with Abhyas academy. I am studying here from 6th class and I am satisfied by its results in my life. I improved a lot here ahead of school syllabus.
Ayan Ghosh
8thIt has a great methodology. Students here can get analysis to their test quickly.We can learn easily through PPTs and the testing methods are good. We know that where we have to practice
Barkha Arora
10thIn terms of methodology I want to say that institute provides expert guidence and results oriented monitering supplements by requsite study material along with regular tests which help the students to improve their education skills.The techniques of providing education helps the students to asses...
Aman Kumar Shrivastava
10thAbhyas academy is great place to learn. I have learnt a lot here they have finished my fear of not answering.It has created a habit of self studying in me.The teachers here are very supportive and helpful. Earlier my maths and science was good but now it has been much better than before.
Barkha Arora
10thBeing a parent, I saw my daughter improvement in her studies by seeing a good result in all day to day compititive exam TMO, NSO, IEO etc and as well as studies. I have got a fruitful result from my daughter.
Prisha Gupta
8thI have spent a wonderful time in Abhyas academy. It has made my reasoning more apt, English more stronger and Maths an interesting subject for me. It has given me a habbit of self studying
Yatharthi Sharma
10thWhen I have not joined Abhyas Academy, my skills of solving maths problems were not clear. But, after joining it, my skills have been developed and my concepts of science and SST are very well. I also came to know about other subjects such as vedic maths and reasoning.
Sharandeep Singh
7thAbout Abhyas metholodology the teachers are very nice and hardworking toward students.The Centre Head Mrs Anu Sethi is also a brilliant teacher.Abhyas has taught me how to overcome problems and has always taken my doubts and suppoeted me.
Shreya Shrivastava
8thMy experience with Abhyas is very good. I have learnt many things here like vedic maths and reasoning also. Teachers here first take our doubts and then there are assignments to verify our weak points.
Shivam Rana
7thA marvelous experience with Abhyas. I am glad to share that my ward has achieved more than enough at the Ambala ABHYAS centre. Years have passed on and more and more he has gained. May the centre flourish and develop day by day by the grace of God.
Archit Segal
7thMy experience with Abhyas Academy has been very good. When I was not in Abhyas whenever teacher ask questions I could not speak it confidently but when I came in Abhyas, my speaking skills developed and now I am the first one to give the answer of teachers question.
Upmanyu Sharma
7thMy experience with Abhyas academy is very nice or it can be said wonderful. I have been studying here from seven class. I have been completing my journey of three years. I am tinking that I should join Abhyas Academy in tenth class as I am seeing much improvement in Maths and English
Hridey Preet
9thUsually we see institutes offering objective based learning which usually causes a lag behind in subjective examinations which is the pattern followed by schools. I think it is really a work of planning to make us students grab the advantages of modes of examination, Objective Subjective and Onli...
Anika Saxena
8thAbhyas institute is one of the best coaching institute in the vicinity of Ambala cantt.The institute provides good and quality education to the students.The teachers are well experienced and are very helpful in solving the problems. The major advantages of the institute is extra classes for weak...
Shreya Shrivastava
8thAbhyas institute is one of the best coaching institute in the vicinity of Ambala Cantt area. The teachers of the institute are well experienced and very helpful in solving the problems of the students.The good thing of the institute is that it is providing extra classes for the students who are w...
Aman Kumar Shrivastava
10thAbhyas Methodology is very good. It is based on according to student and each child manages accordingly to its properly. Methodology has improved the abilities of students to shine them in future.
Manish Kumar
10thMy experience with Abhyas academy is very good. I did not think that my every subject coming here will be so strong. The main thing is that the online tests had made me learn here more things.
