Question

A particle Falls freely from the top of a tower it covers the latter half of the distance in 10(root 2 - 1)second then the time taken to reach the ground is​ options a) 10 sec, b) 10 root 2 sec, c) 20sec,d)20 root 2 sec

Answer 1

Answer:

b) t = 10$\sqrt{2}$

Explanation:

The particle is coming down under the action of gravitational acceleration,

Time taken to travel half distance = $t_{1/2}$

                                                        = 10$\sqrt{2-1}$ sec

                                                        = 10 sec

The formula to calculate height for freely falling bodies = h = $\frac{1}{2}$ g$t^{2}$

height covered in 10 second = $h_{1/2}$ = $\frac{1}{2}$ × 9.8 × 10²

                                                   $h_{1/2}$ = 490 m

total height = h = 490 × 2 = 980m

Now for total height calculating time by using above equation

                   980 = $\frac{1}{2}$ × 9.8 × $t^{2}$

                     $t^{2}$ = $\frac{980 * 2}{9.8}$

                     $t^{2}$ = 200

                                t = $\sqrt{200}$

                                t = 10$\sqrt{2}$

Hope the answer my help!