A 50kg stone is being pushed with a force of 20 N. As a result, the stone is moving at a constant speed of 3m/s. What is the frictional force acting on the stone.
If I am not wrong the answer should be 20 Naccording to the 1st law of newton but why? I just don't get it.
20 N. Because resultant force = 0N. The stone is moving at constant speed thus resultant force = 0 Thus the force u use is use to overcome the friction force of 20n
Question 2
The figure below shows the two horizontal forces acting on the car during a stage of the car motion.
<---------(5000N)-------- [Car] ---------(5000N)---------->
The forward force on the car is then reduced to 1000N, but the backward force remains as 5000N. Calculate the acceleration of the car now.
Ans. -2.67m/s^2
How to arrive at this answer?
clues only like that ?
Yah. That is exactly the question for a book.
Originally posted by BillaMax:Question 2
The figure below shows the two horizontal forces acting on the car during a stage of the car motion.
<---------(5000N)-------- [Car] ---------(5000N)---------->
The forward force on the car is then reduced to 1000N, but the backward force remains as 5000N. Calculate the acceleration of the car now.
Ans. -2.67m/s^2
How to arrive at this answer?
Hi, we need the mass of the car as well because net F = ma
Without the mass of the car, we can only calculate the net force.
it is because the horizontal force = friction.
as the speed of the stone increases, the friction also increases. when friction is equal in magnitude to horizontal force, resultant force=0
at the start it was acceleration cos frictional force was less than horizontal force.
i didnt get it at the start too.:P
My weakest subject.