Pages Covered - 46-47
Chapter - 3
Properties Of Force
They can be represented by arrows. A force has a direction, shown by the direction of the arrow.
A force can make an object change speed. A forward force makes it speed up (accelerate), while a backward force makes it slow down (decelerate).
A force can change the direction in which an object is moving.
A body will remain at rest or will move at a constant speed in a straight line unless acted upon by a resultant force
A resultant force will change the velocity of a body, but as velocity is a vector, a resultant force can change the direction as well as the speed of a body. A resultant force can change both speed and direction at the same time.
Two or more forces for a same line
The two forces acting on the car
Push of engine = 600 N to the right
Drag of air resistance = 400 N to the left.
Working Out resultant force
Resultant force = 600 N−400 N
= 200 N to the right
If no resultant force acts on an object, it will not accelerate; it will remain at rest or it will continue to move at a constant speed in a straight line.
If an object is at rest or is moving at a constant speed in a straight line, we can say that there is no resultant force acting on it.
State whether the forces are balanced or unbalanced
If the forces are unbalanced, calculate the resultant force on the object and give its direction
State how the object’s motion will change.
Answers
All forces are unbalanced expect for b
20n to left, b is balanced, 50n to down
The motion changes due to motion