A car of mass 500 kg is moving with a constant speed of 10 ms–1on a rough horizontal road. Force expended by the engine of the car is 1000 N. Calculate work done in 10 s by:(a) net force on the car (b) gravitational force
(c) the engine (d) frictional force
Answers
Answer:
(a) 0
(b) 0
(c)10000 J
(d) 10000 J
Explanation:
Given,
Mass of the car, m = 500 kg
speed of car = 10 m/s
Force exerted by engine of the car = 1000 N
time take = 10 s
Distance = speed x time
= 10 x 10
= 100 m
(a) Since the care is moving with constant speed so,
acceleration of car, a = 0
hence, net force,F = ma
= m.0
= 0 N
So, work done by net force will be 0.
(b) gravitational force = mg
= 500 x 10 N
= 5000 N
but gravitational force acting perpendicular to the motion of car so work done by gravitational force, W = 0
(c) Since, the engine exerts a force of 1000 N.
work done = force x distance
= 1000 x 100 J
= 10000 J
(d) Let's consider f is frictional force,
then according to question,
force exerted by engine - frictional force = net force
=> 1000 N - f = 0
=> f = 1000 N
so, work done by frictional force = 1000 x 100
= 10000 J
Answer:
I think last one is not good....
Explanation:
I mean part d ...