Fewpal
0 votes
423 views
in Physics by (29.7k points)

Four persons jointly lift a 250 kg box to a height of 1 m and hold it. 

(a) Calculate the work done by the persons in lifting the box. 

(b) How much work is done for just holding the box? 

(c) Why do they get tired while holding it? (g = 10 m/s2). 

Please log in or register to answer this question.

1 Answer

0 votes
by (127k points)

(a) Given, 

Force, F = 250 × 10 = 2500 N 

Displacement, s = 1 m 

Work done = F × s = 2500 × 1 = 2500 J 

(b) As there is no displacement in just holding the box, so no work is done i.e. Work done is zero. 

(c) To hold the box men are applying force against the gravity, which involves their muscles to work, hence they get tired holding it.

Welcome to Sarthaks eConnect: A unique platform where students can interact with teachers/experts/students to get solutions to their queries. Students (upto class 10+2) preparing for All Government Exams, CBSE Board Exam, ICSE Board Exam, State Board Exam, JEE (Mains+Advance) and NEET can ask questions from any subject and get quick answers by subject teachers/ experts/mentors/students.

Categories

...