pls answer it and tell the reason for your answer.
Answers
Answer: A car moving in a straight line in constant speed.
Explanation: This is beause the speed is constant. And to stop it or turn it around, you have to increase or decrease the speed. So therefore there would be an additional force applied to slow it down or speed it up. Newton's law of motion (first) says that an object remains in the same state of motion unless a resultant force acts on it. So moving in a straight line, will cause no additional force to be applied on it. Obiously friction is acting, but I think they haven't assumed friction here
(c) is the correct option
Here we are considering the car as the frame of reference.
Newton's laws of motions are only applicable to inertial frames of reference. Inertial frames are those frames that have no net force acting on them. Since, they are not acted upon by a net force, they do not accelerate and hence are either in a state of rest or constant motion. The property of inertia is applicable to an inertial frame.
So, any option in which car accelerates/retards is a non inertial frame.
In options b and c, car moves with constant speed. But, in option b, the car moves in a circular path, even though speed does not change, the direction of velocity changes at each point of motion and hence we do not get constant velocity.
The only option that fulfills all conditions is (c) as in a straight line uniform motion, (as long as distance = displacement) speed = velocity.