state the nature of work done in the following cases giving justification for each: a) when a truck moves on - Science - Work and Energy

Question

state the nature of work done in the following cases giving
justification for each:
a) when a truck moves on the road , work done by friction
b) work done in pushing a heavy fixed rock
c) work done by a force in lifting a heavy book from a table

Heba Hassan · Answer

(a) When a truck moves on the road, work done by friction is
negative because
it acts opposite to the direction of moving truck (b) Work done in
pushing a heavy fixed rock is positive if it moves along the
directionof applied force, otherwise it is zero (c) Work done by a
force in lifting a heavy book from a table is positive because
theapplied force is acting upwards in which book is lifted

state the nature of work done in the following cases giving justification for each: a) when a truck moves on the road , work done by friction. b) work done in pushing a heavy fixed rock c) work done by a force in lifting a heavy book from a table

state the nature of work done in the following cases giving justification for each:

a) when a truck moves on the road , work done by friction.

b) work done in pushing a heavy fixed rock

c) work done by a force in lifting a heavy book from a table