A body dropped from the top of a tower falls | vedclass

Name: Exam Paper Generator | JEE NEET Paper Generator | Vedclass
Brand: Vedclass
Rating: 5 (35 reviews)

Question

(B) Let $h$ be the height of the tower and $t$ be the total time taken by the body to reach the ground.Given initial velocity $u = 0$ and acceleration

Vedclass · Accepted Answer

$45$

Vedclass · Answer

(B) Let $h$ be the height of the tower and $t$ be the total time taken by the body to reach the ground.Given initial velocity $u = 0$ and acceleration $a = g = 10 \; m/s^2$.The total height is given by $h = \frac{1}{2} g t^2$.The distance covered in the last two seconds is the difference between the total height and the height covered in $(t-2)$ seconds.$40 = \frac{1}{2} g t^2 - \frac{1}{2} g (t-2)^2$.Substituting $g = 10 \; m/s^2$:$40 = 5 t^2 - 5 (t^2 - 4t + 4)$.$40 = 5 t^2 - 5 t^2 + 20 t - 20$.$40 = 20 t - 20$.$60 = 20 t \implies t = 3 \; s$.Now,calculate the height $h$:$h = \frac{1}{2} 	imes 10 	imes (3)^2 = 5 	imes 9 = 45 \; m$.

$A$ body dropped from the top of a tower falls through $40 \; m$ during the last two seconds of its fall. The height of the tower is ..... $m$.

Similar Questions

$A$ body is dropped from a certain height $h$ ($h$ is very large) and a second body is thrown downward with a velocity of $5 \, m/s$ simultaneously. What will be the difference in the heights of the two bodies after $3 \, s$?

$A$ stone is thrown upwards with a velocity $50 \,ms^{-1}$. Another stone is simultaneously thrown downwards from the same location with a velocity $50 \,ms^{-1}$. When the first stone is at the highest point, the velocity of the second stone is $...... \,ms^{-1}$ (Take $g = 10 \,ms^{-2}$).

If the water falls from a dam into a turbine wheel $19.6 \ m$ below,then the velocity of water at the turbines is .................. $m/s$ (take $g = 9.8 \ m/s^2$).

Two balls of the same size,but where the density of one is greater than that of the other,are dropped from the same height. Which ball will reach the Earth first (air resistance is negligible)?

$A$ body is thrown vertically upwards with a velocity $u$. Find the true statement from the following:

Vedclass Test Series

Exam Paper Generator

Online Exam Module