$A$ porter moving vertically upstairs with a load on his head does work. Why?
(N/A) Work is defined as the product of force and displacement in the direction of the force. When a porter moves vertically upstairs,he applies an upward force to balance the weight of the load (acting downwards). Since the displacement of the porter is also in the upward direction,the angle between the force applied by the porter and the displacement is $0^{\circ}$. Therefore,the work done by the porter is positive and non-zero $(W = F \cdot s \cdot \cos(0^{\circ}) = F \cdot s)$.
Explore More
Similar Questions
What happens to the kinetic energy when
$(i)$ the mass of the body is doubled at constant velocity?
$(ii)$ the velocity of the body is doubled at constant mass?
$(iii)$ the mass of the body is doubled but the velocity is reduced to half?
$(i)$ the mass of the body is doubled at constant velocity?
$(ii)$ the velocity of the body is doubled at constant mass?
$(iii)$ the mass of the body is doubled but the velocity is reduced to half?
Medium
View SolutionDoes work done depend upon the velocity of the body?
Easy
View SolutionWhat is horsepower?
Easy
View Solution$(i)$ An object thrown at a certain angle to the ground moves in a curved path and falls back to the ground. The initial and the final points of the path of the object lie on the same horizontal line. What is the total work done against the force of gravity and by the force of gravity on the object? Explain with proper mathematical expression.
$(ii)$ $A$ certain force acting on a $20 \, kg$ mass changes its velocity from $5 \, m s^{-1}$ to $2 \, m s^{-1}$. Calculate the work done by the force.
$(ii)$ $A$ certain force acting on a $20 \, kg$ mass changes its velocity from $5 \, m s^{-1}$ to $2 \, m s^{-1}$. Calculate the work done by the force.
Medium
View SolutionThe work done in lifting a box onto a platform does not depend upon how fast it is lifted up. Explain your answer giving proper reasoning.
Easy
View SolutionVedclass Products
For Students
Vedclass Test Series
Mock tests in real JEE/NEET style with performance analysis. 5-day free trial.
Start Free TrialFor Teachers
Exam Paper Generator
Generate Set A/B/C/D exam papers from 7.5L+ questions in 2 minutes. 3 chapters free.
Try FreeFor Institutes
Online Exam Module
Live online exams with unlimited students, 360° analytics & white-label branding.
See Demo