Take Class 11 Tuition from the Best Tutors
Affordable fees 1-1 or Group class Flexible Timings Verified Tutors Search in
The sign of work done by a force
on a body is important to understand. State carefully if the following
quantities are positive or negative:
(a) Work done by a man in lifting a bucket out of a well by means of a rope tied to the bucket,
(b) Work done by gravitational force in the above case,
(c) Work done by friction on a body sliding down an inclined plane,
(d) Work done by an applied force on a body moving on a rough horizontal plane with uniform velocity,
(e) Work done by the resistive force of air on a vibrating pendulum in bringing it to rest.
Asked by Abhay Last Modified
Answer 
Dharmendra Kumar
A teacher's purpose is not to create students in this own image, but to develop students who creates their own image.
A) positive
In a given case, force and displacement are in the same direction. Hence the sign of work done is positive. In this case the work is done on bucket.
(b) negative
In this case, the direction of force and displacement are opposite to each other. Hence, the sign of work done is negative.
(c) negative
Since the direction of frictional force is opposite to the direction of motion, the work done by frictional force in negative.
(d) positive
Here the body is moving on a rough horizontal plane. Frictional force oppose the motion body. Therefor in order to mention a uniform velocity a uniform force must be apply to body. Since the applied force at in the direction of motion of the body the work down is positive.
(e) - Negative
The resistive force of air act in the direction opposite to the direction of motion of pendulum. Hence the work done is negative.
read lessView 1 more Answers
Related Questions
The moment of inertia of a body about a given axis is 1.2kgm^2 . Initially the body is at rest. In order to produce a rotational kinetic energy of 1500J, an angular acceleration of 25rad/second ^2 must be applied about that axis for a duration of
Now ask question in any of the 1000+ Categories, and get Answers from Tutors and Trainers on UrbanPro.com
Ask a QuestionRelated Lessons
Recommended Articles
Science, Arts Or Commerce - Which One To Go For?
Once over with the tenth board exams, a heavy percentage of students remain confused between the three academic streams they have to choose from - science, arts or commerce. Some are confident enough to take a call on this much in advance. But there is no worry if as a student you take time to make choice between - science,...
Read full article >
Top Benefits of e-Learning
With the current trend of the world going digital, electronic renaissance is a new movement that is welcomed by the new generation as it helps makes the lives of millions of people easier and convenient. Along with this rapidly changing movement and gaining popularity of Internet, e-Learning is a new tool that emerging...
Read full article >
The Rising Problems in Indian Government School
With the mushrooming of international and private schools, it may seem that the education system of India is healthy. In reality, only 29% of children are sent to the private schools, while the remaining head for government or state funded education. So, to check the reality of Indian education system it is better to look...
Read full article >
The Trend of E-learning and it’s Benefits
E-learning is not just about delivering lessons online. It has a much broader scope that goes beyond manual paper or PowerPoint Presentations. To understand the reach of E-learning and how the whole process works in developing the Educational system, we will discuss a few points here. Let us find out how this new learning...
Read full article >
Looking for Class 11 Tuition ?
Learn from the Best Tutors on UrbanPro
Are you a Tutor or Training Institute?
Join UrbanPro Today to find students near youThe best tutors for Class 11 Tuition Classes are on UrbanPro
The best Tutors for Class 11 Tuition Classes are on UrbanPro
21
