badge image

Enroll For Free Now & Improve Your Performance.

×
User Icon
User Icon
User Icon
User Icon
User Icon

Thank you for registering.

One of our academic counsellors will contact you within 1 working day.

Please check your email for login details.
MY CART (5)

Use Coupon: CART20 and get 20% off on all online Study Material

ITEM
DETAILS
MRP
DISCOUNT
FINAL PRICE
Total Price: Rs.

There are no items in this cart.
Continue Shopping
Menu
Grade: upto college level

                        

An engineer wants to design an improved elevator for a building The original design used a motor that could lift 1000 kg through a distance of 20 meters in 30 seconds. The engineer wants a motor that can lift 800 kg through a distance of 30 meters in 20 seconds. Compared to the old motor, the new motor (A) should exert a force of the same magnitude, but must provide a larger power output. (B) should exert a force of a larger magnitude, and must provide a larger power output. (C) can exert a force of a smaller magnitude, and can provide the same power output. (D) can exert a force of a smaller magnitude, but must provide a larger power output. (E) can exert a force of a smaller magnitude, but must provide a larger power output.

5 years ago

Answers : (1)

Deepak Patra
askIITians Faculty
471 Points
							Earth revolves around the Sun in a perfectly circular orbit. The displacement of the Earth in the circular motion around the Sun is along the tangent to the orbit whereas the force of Sun is along the radius vector of the circle. These two vectors will be orthogonal to each other that mean both the vector will make 90̊ to each other.
Since work done by the force F on an object which is displaced by a distance s is defined as,
W = F. s
= Fs cos ϕ …… (1)
Where ϕ is the angle between F and s and here the value of ϕ is 90̊ .
So, cos ϕ = cos 90̊
= 0 …… (2)
Putting the value of equation (2) in equation (1),
W = F. s
= Fs cos ϕ
= (Fs) (0)
= 0 …… (3)
From equation (3) we observed that, the work done by the Sun on the Earth will be zero.
5 years ago
Think You Can Provide A Better Answer ?
Answer & Earn Cool Goodies


Course Features

  • 101 Video Lectures
  • Revision Notes
  • Previous Year Papers
  • Mind Map
  • Study Planner
  • NCERT Solutions
  • Discussion Forum
  • Test paper with Video Solution


Course Features

  • 110 Video Lectures
  • Revision Notes
  • Test paper with Video Solution
  • Mind Map
  • Study Planner
  • NCERT Solutions
  • Discussion Forum
  • Previous Year Exam Questions


Ask Experts

Have any Question? Ask Experts

Post Question

 
 
Answer ‘n’ Earn
Attractive Gift
Vouchers
To Win!!! Click Here for details