A projectile's horizontal range on level ground is R= [(Vo)^2 sin2θ] / g. At what launch angle or angles will the projectile land at half of its maximum possible range.

15° and 75°

Explanation:

Given:

The range of a projectile motion is given as:

Where,

Maximum possible range is when

So, maximum range possible is,

Now, as per question:

Therefore, the launch angles are 15 degree and 75 degree.

answer: the rock sample is a sedimentary rock.

explanation:

it is given that:

mass of rock sample, m = 2.7 g

volume of rock sample,

so, density of rock sample will be

since, the density of rock sample is . hence, the rock sample is a sedimentary rock, whose densities varies between .