# Motion Under Gravity | Definition, Examples, Equation – Motion in a Straight Line

## Motion Under Gravity | Definition, Examples, Equation – Motion in a Straight Line

We are giving a detailed and clear sheet on all Physics Notes that are very useful to understand the Basic Physics Concepts.

Motion Under Gravity Definition:
The motion under gravity refers to the movement of an object whose vertical motion is affected by the presence of gravity.

Motion Under Gravity Equations:
If an object is falling freely (u = 0) under gravity, then equations of motion becomes
(i) v = u + gt
(ii) h = ut + $$\frac{1}{2}$$ gt²
(iii) v² = u² + 2gh

Note:
If an object is thrown upward then g is replaced by – g in above three equations.
It thus follows that:
(i) Time taken to reach maximum height, tA = $$\frac{u}{g}=\sqrt{\frac{2 h}{g}}$$
(ii) Maximum height reached by the body, hmax = $$\frac{u^{2}}{2 g}$$
(iii) A ball is dropped from a building of height h and it reaches after t seconds on earth. From the same building if two ball are thrown (one upwards and other downwards) with the same velocity u and they reach the earth surface after t1 and t2 seconds respectively, then
$$t=\sqrt{t_{1} t_{2}}$$
(iv) When a body is dropped freely from the top of the tower and another body is projected horizontally from the same point, both will reach the ground at the same time.

Motion in a Straight Line Topics: