The three examples in which friction helps us or makes things easier in our daily life are :
(a) Friction helps us to walk. if there were no friction, we wouldn't be able to push earth backwards by our feet . Thus we will not get the reaction force from earth which is necessary for walking.
(b) Conveyor belts will not work if there is no friction. Friction provides a grip for the conveyor belts to transfer motion from one part of a machine to another.
(c) Cars, buses and all locomotives will not be able to stop once they are set in motion if the friction was absent. friction provides a braking forces for these vehicles to stop.
Yes. Acceleration means any change in speed or direction of motion. When an object coasts in a circular orbit at constant speed around the Earth, its direction is constantly changing. The acceleration is "CENTRIPETAL", which points toward the center of the circle.
