Explanation:
We start by using the conservation law of energy:

or

Simplifying the above equation, we get

We can rewrite this as

Note that the expression inside the parenthesis is simply the acceleration due to gravity
so we can write

where
is the launch velocity.
Answer:
Vi = 94.64 m/s
Explanation:
I order to find out the initial velocity of the object, we can use third equation of motion:
2ah = Vf² - Vi²
where,
a = acceleration = -9.8 m/s²
h = maximum height covered by object = 460 m - 3 m = 457 m
Vf = Final Velocity = 0 m/s (since, object momentarily stops at highest point)
Vi = Initial Velocity = ?
Therefore,
2(-9.8 m/s²)(457 m) = (0 m/s)² - Vi²
Vi = √8957.2 m²/s²
<u>Vi = 94.64 m/s</u>
Answer:

I guess you can round it to 11 seconds.
Explanation:
Going with a speed 9m/s means you are going 9 meters in each second.
If you are going 9 meters in second how many seconds will it take to 100 meters?
Visually;
9 meters - - - 1 second
100 meters - - - ?seconds.
When you write like this 9 times ?seconds equal to 100 meters time 1 second. (you probably know this but just in case)
So to find ?second you multiply 100meters by 1 and divide it by 9 whixh will give you 11.1111 seconds whixh again I believe you can round it to 11.
(Kind of a) Proof;
If 9m * ?sec = 100 m * 1 sec
you send 9 meters to other side.
?sec = (100 m * 1 sec) ÷ 9m
Hope it was clear and it helps! Please let me know if you have any questions.
Explanation:
ask to nirajan shrestha
search on fb
he is good science teacher❣❣❣