a stone is dropped from the upper observation deck of a tower, 450 m above the ground. How long does it take for the stone to reach the ground

9.49 s

Explanation:

Applying,

s = ut+gt²/2 Equation 1

Where s = heigth of the deck, u = initial velocity, t = time, g = acceleration due to gravity.

From the question,

Given: s = 450 m, u = 0 m/s( dropped from height)

Constant: g = 10 m/s²

Substitute these values into equation 1

450 = (0×t)+10t²/2

450 = t²

5t² = 450

t² = 90

t = √90

t = 9.49 s

a person with a mass of 106kg has a weight of 1060n

a.metals can become magnetic if they have many spinning electrons that create magnetic fields.d.only some metals are attracted by magnets; these metals are called ferromagnetic.

d.wrapping an insulated wire around a metal with ferromagnetic properties and applying an electric current.