Answer:
a.18.5 m/s
b.1.98 s
Explanation:
We are given that

a.Let
be the initial velocity of the ball.
Distance,x=30 m
Height,h=1.8 m





Substitute the values





Initial velocity of the ball=18.5 m/s
b.Substitute the value then we get

t=1.98 s
Hence, the time for the ball to reach the target=1.98 s
If I remember correctly (from my studies long time ago) the layers are from the outer to the center:
SiAl : Silicon-Aluminum
SiMa : Silicon-Magnesium (although should be Mg)
NiFe : Nickel-Iron
The SiMa layer should have the lightest elements (Magnesium is lighter than Aluminum)
30x30=900
The answer is 900 meters after 30 seconds
Answer:
The distance between the camera and the rock is 836.6 cm
Explanation:
A right triangle is formed where the hypotenuse (h) is the distance between the rock and the camera. One of the leg (l) is the distance between the camera and the surface. The angle between the hypotenuse and this leg is α = 90° - 13.69° = 76.31°. By definition:
cos α = adjacent/hypotenuse
cos(76.31) = 198.0/h
h = 198.0/cos(76.31)
h = 836.6 cm