A ball is dropped from a tower of height 80 , | vedclass

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

Question

(B) Total height $H = 80 \,m$. The last $50 \%$ of the fall corresponds to the distance from $40 \,m$ to $80 \,m$ from the top.Let $t_1$ be the time t

Vedclass · Accepted Answer

$1.17 \,s$

Vedclass · Answer

(B) Total height $H = 80 \,m$. The last $50 \%$ of the fall corresponds to the distance from $40 \,m$ to $80 \,m$ from the top.Let $t_1$ be the time taken to fall the first $40 \,m$ (first $50 \%$ of the height).Using $s = ut + \frac{1}{2}at^2$ with $u = 0$ and $a = 10 \,ms^{-2}$:$40 = 0 + \frac{1}{2} 	imes 10 	imes t_1^2$$40 = 5 t_1^2 \Rightarrow t_1^2 = 8 \Rightarrow t_1 = \sqrt{8} = 2 \sqrt{2} \,s \approx 2.828 \,s$.Let $t_2$ be the total time taken to fall the entire height of $80 \,m$.$80 = 0 + \frac{1}{2} 	imes 10 	imes t_2^2$$80 = 5 t_2^2 \Rightarrow t_2^2 = 16 \Rightarrow t_2 = 4 \,s$.The time taken to cover the last $50 \%$ of the fall is $\Delta t = t_2 - t_1$.$\Delta t = 4 - 2 \sqrt{2} = 4 - 2.828 = 1.172 \,s \approx 1.17 \,s$.

$A$ ball is dropped from a tower of height $80 \,m$. The time it takes to cover the last $50 \%$ of its fall is (acceleration due to gravity $= 10 \,ms^{-2}$)

Similar Questions

$A$ person standing on the floor of an elevator drops a coin. The coin reaches the floor in time $t_{1}$ if the elevator is at rest and in time $t_{2}$ if the elevator is moving uniformly. Then

$A$ ball is dropped and its displacement versus time graph is as shown (Displacement $x$ from ground and all quantities are positive upwards).
$(a)$ Plot qualitatively velocity versus time graph.
$(b)$ Plot qualitatively acceleration versus time graph.

Two balls $A$ and $B$ are thrown with the same velocity $u$ from the top of a tower. Ball $A$ is thrown vertically upwards and ball $B$ is thrown vertically downwards. Choose the correct statement.

$A$ ball is released from the top of a tower of height $h$ meters. It takes $T$ seconds to reach the ground. What is the position of the ball at $T/3$ seconds?

Vedclass Test Series

Exam Paper Generator

Online Exam Module