Physics Class X Sindh Textbook Board

1. Attempt all Questions.
Q.1: a) Define work, positive and negative work and the unit of work?
b) An object weighing 10 N falls through a distance of 12m. What is its velocity just before it strikes the
ground? Assume there is no air friction?
c) A body having the mass of 5 kg is moving in a circle having the radius 3m producing centripetal
acceleration of 5 m/s2 and starts from point A and covers distance of two circles in 5 sec and return
back to point A then what will be its total work?
Q.2: a) What is the power of an engine that pulls a 1250 Kg car at a steady speedof 12 m/s along a level
road?
b) What is potential energy and define its two types?
c) If the velocity of body increases 3 times then what will be its kinetic energy?
Q.3: a) How much work is done to displace horizontally a body 50 m by a force of 300 N, whose angle
with the horizontal is 45o?
b) What is power and what are the units of power?
c) In equilibrium there is no change in velocity of body or body is at rest it means that the acceleration
of the body is zero. Does it mean that total work on body will be zero?