Question

Which of the following is an example of curvilinear motion?
${\text{A}}{\text{.}}$ An apple falling from a tree
${\text{B}}{\text{.}}$ A spinning wheel
${\text{C}}{\text{.}}$ The motion of a pendulum
${\text{D}}{\text{.}}$ Throwing of a javelin

Answer 1

Hint- Here, we will proceed by discussing when a motion is known as curvilinear motion. Then, we will find out the motion corresponding to the activities mentioned in the option separately.

Complete step by step answer:
Curvilinear motion is defined as motion that occurs when a particle travels along a curved path. The curved path can be in two dimensions (in a plane), or in three dimensions. This type of motion is more complex than rectilinear (straight-line) motion.
An apple falling from a tree will fall in a straight line due to acceleration due to gravity and hence, this motion will be rectilinear motion.
A spinning wheel undertakes circular motion when it is in motion because the spinning wheel rotates about the centre of the wheel.
The motion of a pendulum is simple harmonic motion (SHM) because the pendulum oscillates about a mean position and has two extreme positions. At the mean position of the SHM, the velocity is maximum and the acceleration is zero whereas at the extreme position of the SHM, the velocity is zero and the acceleration is maximum.
Throwing of a javelin at some angle with the horizontal will occur in the development of an acceleration at some angle with the velocity so the path followed will be a curved path and hence, we call this motion a curvilinear motion.
Therefore, throwing of a javelin is an example of curvilinear motion.
Hence, option D is correct.

Note- Some other examples of curvilinear motion are cyclist racing on curved tracks of velodrome, earth moving around the sun, a car taking a turn on a road, a ball thrown upwards at an angle, motion of a snake, spinning top (for rotatory motion also), motion of an earthworm, motion of a spring.