A target lies flat on the ground 3m from the side of a building which is 10m tall. A student rolls a ball off the horicontal roof of the building in the direction of the target. Air resistance is negligible. Te horizonal speed with which the ball must leave the roof if it is to srike the target is most nearly
a) 3/10 m/s
b)sqrt(2) m/s
c)3/sqrt(2)
d)3m/s
e)10sqrt(5/3) m/s
time to fall=sqrt( 2height/g)
horizontal velocity= 3/time to fall
You need to put some thinking down. For me to answer is not helpful to you.
jf, john ur a complete asswipe
To find the horizontal speed with which the ball must leave the roof in order to strike the target, we can use the following steps:
Step 1: Calculate the time it takes for the ball to fall from the roof to the ground.
Given:
Height of the building = 10m
Acceleration due to gravity (g) = 9.8 m/s^2
Using the formula:
time to fall = sqrt(2 * height / g)
time to fall = sqrt(2 * 10 / 9.8)
time to fall ≈ 1.43 seconds
Step 2: Calculate the horizontal velocity.
Given:
Distance from the building to the target = 3m
Using the formula:
horizontal velocity = distance / time
horizontal velocity = 3 / 1.43
horizontal velocity ≈ 2.10 m/s
Therefore, the horizontal speed with which the ball must leave the roof to strike the target is most nearly 2.10 m/s.
Thus, the correct answer is not listed among the options provided.
To solve this problem, we need to find the initial horizontal velocity with which the ball must be launched from the roof of the building in order to hit the target.
First, let's calculate the time it takes for an object to fall from the roof of the building to the ground. We can use the equation:
time to fall = sqrt(2 * height / g)
where height is the height of the building (10m) and g is the acceleration due to gravity (approximately 9.8 m/s^2). Plugging in the values, we get:
time to fall = sqrt(2 * 10 / 9.8) ≈ 1.43 seconds
Now, we can calculate the horizontal velocity needed to hit the target. The horizontal velocity is calculated by dividing the horizontal distance to the target (3m) by the time it takes to fall.
horizontal velocity = 3m / 1.43s ≈ 2.1 m/s
Therefore, the correct answer is approximately 2.1 m/s. However, none of the given options match this value. Therefore, it seems that there might be an error in the solution or the answer choices provided.