First Law Of Motion Definition Class 9

Newton s first law of motion states that a body remains in the state of rest or uniform motion in a straight line unless and until an external force acts on it.

First law of motion definition class 9.

Newton s first law of motion force and laws of motion get topics notes online test video lectures doubts and solutions for cbse class 9 on topperlearning. Velocity is a vector quantity which expresses both the object s speed and the direction of its motion. The first law states that if the net force the vector sum of all forces acting on an object is zero then the velocity of the object is constant. The first law of motion is stated as an object remains in a state of rest or of uniform motion in a straight line unless compelled to change that state by an applied force.

It requires some force from the outside to cause such a change. Therefore the statement that the object s velocity is constant is a statement that both its speed and the direction of its motion are constant. Inertia is of three types namely inertia of rest inertia of motion and inertia of direction. The tendency of undisturbed objects whether they are at rest or moving with uniform velocity is called inertia.

Newton s first law of motion. Car or bus starts suddenly passengers fall backward galileo s law of inertia hanging carpet is beaten with stick inertia it is dangerous to jump out of moving bus its fruits and leaves fall down newton s first law of motion the dust particles start coming out of it tree is shaken vigorously. There are two conditions. The first law of motion implies that things cannot start stop or change direction all by themselves.

Hence the first law of motion is also known as the law of inertia. Body at rest body in motion. According to the law any object in the universe remains in its state of rest or uniform motion. This property of massive bodies to resist changes in their state of motion is called inertia.

The inability of any object to change its state is called inertia. All objects resist a change in their state of motion.