Physics Help

Hi there, ive started to revise for my physics exam and theres one thing that i dont understand at all.
Its about forces and acceleration :
Precisely resultant force:
I dont understand "If theres no resultant force on a moving object itll just carry on moving at the same velocity"

How can this be true ?? :s-smilie:

If a car has a driving force of 1000N to the left and the air resistance is also 1000N to the right , that car wont move????

Reply 1

iMacJack

No, it will continue to go at the same speed because it's constantly velocity, however, if both the forces were 0N, the car would indeed be stationery, whenever the resultant force is over 0N and are are equal, for example, 400 left 400 right, the car will remain at a constant speed.

Reply 2

aoxa

Original post by Shahid786

If a car has a driving force of 1000N to the left and the air resistance is also 1000N to the right , that car wont move????

The car will move. When the resultant force is zero, the object is either stationary, or is moving at a constant velocity.

If the object is already moving, it'll keep moving at the same speed. If the object is stationary, it'll remain stationary.

When the object has a resultant force (resultant force is not zero) then the object will either accelerate or decelerate depending on the direction of the force.