Unit
3
Dynamics
Q5: Define net force?
Net
force:
Net force is the
resultant of all the forces acting on a body.
Q6: State Newton’s
first law of motion with example?
First law of
motion:
A body continues its
state of rest or of uniform motion in a straight line provided no net force
acts on it.
For example, a book
lying on a table remains at rest as long as no net force acts on it.
Similarly, a ball
rolled on a frictionless ground never stop as long as no net force acts on it.
Long Q1. Explain
Newton’s First law of motion?
First law of
motion:
A body continues its
state of rest or of uniform motion in a straight line provided no net force
acts on it.
Explanation:
According to Newton's
first law of motion, a body at rest remains at rest provided no net force acts
on it. This part of the law is true as we observe that objects do not move by
themselves unless someone moves them.
For example, a book
lying on a table remains at rest as long as no net force acts on it.
Similarly, a moving
object does not stop moving by itself. A ball rolled on a rough ground stops
earlier than that rolled on a smooth ground. It is because rough surfaces offer
greater friction. If there would be no force to oppose the motion of a body then
the moving body would never stop. Since Newton's first law of motion deals with
the inertial property of matter,
therefore, Newton's
first law of motion is also known as law of inertia.
Q7 : What is the law of
inertia?
Law of Inertia:
Newton's first law of
motion deals with the inertial property of matter, therefore, Newton's first
law of motion is also known as law of inertia. A body continues its state of
rest or of uniform motion in a straight line provided no net force acts on it.
Q8 Why does a passenger
move outward when a bus takes a turn?
When a bus takes a
sharp turn, passengers fall in the outward direction. It is due to inertia that
they want to continue their motion in a straight line and thus fall outwards.
