Difference between Linear motion and Rotational motion
Linear motion:
1.) The motion of object along the straight line is known as linear motion.
Eg. Motion of children doing cycling, cars running on road etc.
2.) The distance travelled by object is always measured as straight line.
3.) If the starting point and ending point of motion is along a same straight path, then the magnitude of distance is equal to that of distance.
4.) The rate of change of displacement is known as linear velocity, given by
5.) The acceleration of object in the motion is rate of change of velocity. The formula for the acceleration can be written as
a = ∆v/∆t
6.) The inertia in linear motion is contributed by mass and velocity of object.
7. The equations for motion to study displacement, velocity and acceleration are given as
- First equation of motion, v = u + at
- Second equation of motion, s = ut + 1/2 at^2
- Third equation of motion, v^2 = u^2 + 2as
8.) According to Newton’s second law of motion force responsible to produce linear motion is given as, F=mass × acceleration.
Rotational motion:
1.) The motion of object around fix point or object is known as rotational motion
Eg. Motion of children in merry-go-round, motion of blades of fan etc.
2.) The distance travelled by object is always measured as in terms of angle described by object with centre.
3.) The parameters like displacement, velocity and acceleration are changed as angular displacement, angular velocity and angular acceleration.
4.) The rate of change of angular displacement is known as angular velocity. Denoted by omega (ω), given by
ω = ∆θ/∆t
SI unit is rad/s
5.) The angular acceleration of object in the motion is rate of change of angular velocity. Denoted by alpha (α) The formula for the acceleration can be written as
α = ∆ω/∆t
SI unit is rad/s2
6.) The inertia in linear motion is contributed by mass and square of distance of the particle form the axis of rotation Here it is termed as moment of inertia.
7.) The equations for motion to study angular displacement, angular velocity and angular acceleration are given as
- First equation of motion, ω = ω0 + αt
- Second equation of motion, θ = ω0 t + 1/2 αt2
- Third equation of motion, ω2 = ω0 2 + 2αθ
Where, ω0 = initial angular velocity , ω = final angular velocity
8.) To produce rotational motion, torque is responsible which is given by,
Torque = moment of inertia × angular acceleration.