Question

an object is thrown vertically upward and reaches a hight of 78.4 m. calculate the velocity?(g=9.8)

Answer 1

$39.2 \: \: \frac{m}{sec}$

Please refer the above photograph for the used process.


KEY POINTS TO REMEMBER :-


☸️ Equations of motion.

These are the relations established between important terms of motion like velocity, time, distance and acceleration.


☸️ Equation used in solving the question is :-

${v}^{2} - {u}^{2} = 2as$

Where,
V is the final velocity.
U is the initial velocity.
A is the acceleration.
(But in this case 'A' is the acceleration due to gravity that is 'g' as the object is thrown up)

S is the distance covered by the object.


☸️ V in this case is equal to 0 m/sec because after reaching the maximum height, the object comes to rest.


☸️ A = (-9.8 m/sec²) as the motion of the object is against (opposite) the direction of motion.


☸️ Answer = 39.2 m/sec



Thanks!

Answer 2

this is answer of this question