## 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, t_{A} = \(\frac{u}{g}=\sqrt{\frac{2 h}{g}}\)

(ii) Maximum height reached by the body, h_{max} = \(\frac{u^{2}}{2 g}\)

(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 t_{1} and t_{2} 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:**