Forces and Their Effects - from the P2 AQA syllabus

Forces and their effects

Resultant forces:

* Whenever two objects interact, the forces they exert on each other are equal and opposite.

* A number of forces acting at a point may be replaced by a single force that has the same efefct on the motion as the original forces acting together This single force is called the resultant force .

* A resultant force acting on an object may cause a change in its state of rest or motion.

* If the resultant force acting on a stationary object is: zero, the object will remain stationary; not zero, the object will accelerate in the direction of the resultant force.

* If the resultant force acting on a moving object is : zero, the object will continue to move at the same speed and in the same direction; not zero, the object will accelerate in the direction of the resultant force.

Forces and motion:

* The acceleration of an object is determined by the resultant force acting on the object and the mass of the object: a=F/m or F=mxa.

* The gradient of a distance-time graph represents speed.

* Calculation of speed of an object from the gradient of a distance-time graph is done by the equation s=d/t.

* The velocity of an object is its speed in a given direction.

* The acceleration of an object is given by the equation a= v-u/t.

* The gradient of a velocity-time graph…