Consider a vehicle going on a horizontal road towards east. Neglect any force due to air. The frictional force on the vehicle by the road
A Is towards east if the vehicle is accelerating
B Is zero if the vehicle is moving with a uniform velocity
C Must be towards east
D Must be towards west.
Ans 1:
Class : Class 10
see guys, i think u all are mistaken. We dont consider in what direction the car is going, but in which direction the wheel is turning. for the car to go forwards, the wheel must roll clockwise. so for the car to go east, wheel must roll in the clockwise direction. Now consider a very small part of the wheel which is touching the ground. to wheel to roll in clockwise direction , that small part must slide backward, and that must continously happen in order for wheel to turn clockwise and car to go in east direction. And u know, friction is b/w the surface in contact, i.e the rolling part of the wheel, not with the car. so friction should oppose the backward-going part of the wheel, and thus in the ame direction with the motion of the car. if friction were to be in west, the car would never go in east direction, because the wheel would'nt have any force to oppose, to make it go in that direction, and thus the car would never be able to go towards the east direction!
Ans 2:
Class : Class 8
I think that option "D" is the correct answer as friction is always opposite to direction of motion of the object
Ans 4:
Class : Class 8
the answer has to be d because friction always oppose the relative motion of an object no matter if it accelerates or not.
Ans 7:
Class : Class 9
The correct answer is d as friction acts opposite to the direction of the applied force
Ans 9:
Class : Class 8
How can the direction of friction be towards east? It should always act in the direction opposite to that of the direction of the moving body, i.e., friction should act towards the west irrespective of whether the vehicle is accelerating or retarding. So the correct answer should be D!
Ans 17:
Class : Class 9
I'm confused about the same thing...friction opposes relative motion, so it will obviously be towards west??