what are the similarities and differences between straight-line motion, circular motion, and projectile motion?

Linear motion involves an object moving in a straight line in one dimension, like a car driving on a perfectly straight road, while projectile motion involves two dimensions, like a cannonball firing. Circular motion occurs in a circle, such as when a ball whirls on a string.

Explanation:

Uniform Motion in a Straight Line. If a body travels in a straight line and covers an equal amount of distance in an equal interval of time, then it is said to have uniform motion. In simple words, a body is said to have uniform acceleration if the rate of change of its velocity remains constant. A straight line does not mean that the object is not moving! This graph shows increasing speed. In physics, circular motion is a movement of an object along the circumference of a circle or rotation along a circular path. It can be uniform, with constant angular rate of rotation and constant speed, or non-uniform with a changing rate of rotation.There are three mathematical quantities that will be of primary interest to us as we analyze the motion of objects in circles. These three quantities are speed, acceleration and force. The speed of an object moving in a circle is given by the following equation. Projectile motion is a form of motion experienced by an object or particle that is projected near the Earth's surface and moves along a curved path under the action of gravity only. This curved path was shown by Galileo to be a parabola, but may also be a line in the special case when it is thrown directly upwards.