Answer:
The height of the building is 88.63 m.
Explanation:
Given;
initial component of vertical velocity,
= 12 m/s sin 26° = 5.26 m/s
initial horizontal component of the velocity,
= 12 m/s cos 26° =10.786 m/s
horizontal distance traveled by the rock, x = 40.4 m
time of flight is calculated as;
x =
t
t = x / 
t = 40.4 / 10.786
t = 3.75 s
Determine the final vertical velocity of the ball;

Determine the height of the rock;

Therefore, the height of the building is 88.63 m.
Answer:
Explanation:
a = F/m = 7500/2000 = 3.75 m/s²
v² = u² + 2as
s = (v² - u²) / 2a
s = (0² - 45²) / (2(-3.75))
s = 270 m
We can answer this one very quickly. From the <em>Law of Conservation of Energy</em>, we know that "Energy can't be created or destroyed.".
So that only leaves us one way to complete the sentence in this question:
"One form of energy can be <em>transformed into</em> another type of energy.
" <em>(B)</em>
Wave speed = (wavelength) x (frequency)
Wave speed = (3 m) x (15 Hz)
<em>Wave speed = 45 m/s</em>