A squirrel drops an acorn onto the head of an unsuspecting dog. The acorn falls 20 m before it lands on the dog. Ignore air resistance. How many seconds did the acorn fall?

2 seconds

Explanation:

From the question,

Applying the equation of motion for a body falling under gravity

s = ut+1/2gt² Equation 1

Where, s = hieght of fall, u = initial velocity, t = time, g = acceleration due to gravity.

Given: s = 20 m, u = 0 m/s, t = ?, g = 10 m/s²

Substitute these values into equation 1

10 = 0(t²)+1/2(10×t)

10 = 5t

Solve for t

5t/5 = 10/5

t = 2 seconds

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 .

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