Answer:
24.2 m/s
Explanation:
The stone strikes the ground at an angle of 45 degrees: this means that its vertical velocity is equal (in magnitude) to its horizontal velocity, in fact:
![tan \theta = \frac{|v_y|}{v_x}\\tan 45^{\circ} = 1 \rightarrow |v_y| = v_x](https://tex.z-dn.net/?f=tan%20%5Ctheta%20%3D%20%5Cfrac%7B%7Cv_y%7C%7D%7Bv_x%7D%5C%5Ctan%2045%5E%7B%5Ccirc%7D%20%3D%201%20%5Crightarrow%20%7Cv_y%7C%20%3D%20v_x)
The motion along the vertical direction is a uniformly accelerated motion, so we can find the final vertical velocity using the following suvat equation
![v_y^2 -u_y^2 = 2as](https://tex.z-dn.net/?f=v_y%5E2%20-u_y%5E2%20%3D%202as)
where
is the final vertical velocity
is the initial vertical velocity (zero because the stone is thrown horizontally)
is the acceleration of gravity (we take downward as positive direction)
s = 30 m is the vertical displacement
Solving for vy,
![v_y = \sqrt{u_y^2+2as}=\sqrt{0+2(9.8)(30)}=24.2 m/s](https://tex.z-dn.net/?f=v_y%20%3D%20%5Csqrt%7Bu_y%5E2%2B2as%7D%3D%5Csqrt%7B0%2B2%289.8%29%2830%29%7D%3D24.2%20m%2Fs)
This means that the horizontal velocity is also 24.2 m/s: and since the horizontal velocity is constant during the whole motion (there is no acceleration in the horizontal direction), this means that the stone was thrown exactly at 24.2 m/s.
Because those layers have been in existence longer than the layer on top of it.
Lightning heats the air so rapidly that it creates a shock wave that we call thunder.
Answer:
sorry I hate when people press your question and answer with a fake answer for points, however you said it was 100 points and it's not even close lol but it is "your speed Is constant" that is not true