Any object remains in the state of rest or in uniform motion along a straight line until it is compelled to change the state by applying an external force.
Explanation: If an object is in the state of rest, then it will remain in rest until an external force is applied to change its state. Similarly, an object will remain in motion until an external force
is applied over it to change its state. This means all objects resist in changing their state. The state of any object can be changed by applying external forces only.
Newton’s First Law of Motion in Everyday Life :
- A person standing in a bus falls back when the bus starts moving suddenly. This happens because the person and bus both are in rest while the bus is not moving, but as the bus starts moving, the legs of the person start moving along with bus but rest portion of his body has the tendency to remain in rest. Because of this, the person falls backwards; if he is not alert.
- A person standing in a moving bus falls forward if the driver applies brakes suddenly. This happens because when the bus is moving, the person standing in it is also in motion along with bus. But when the driver applies brakes the speed of bus decreases suddenly or bus comes in the state of rest suddenly, in this condition the legs of the person which are in contact with the bus come in rest while the rest part of his body has the tendency to remain in motion. Because of this person falls forward if he is not alert.
- Before hanging the wet clothes over laundry line, usually many jerks are given to the clothes to get them dried quickly. Because of jerks, droplets of water from the pores of the cloth falls on the ground and a reduced amount of water in clothes dries them quickly. This happens because when suddenly clothes are made in motion by giving jerks, the water droplets in it have the tendency to remain in rest and they are separated from clothes and fall on the ground.
