1) a stone is dropped from their top of a tower. if it reaches the earth in 6 seconds, the height of the 3 tower is nearly:
a) 360 m b) 180 m c)100 m d) 60 m

2) a car accelerates from rest at a constant rate for the first time 10 seconds and converts
a distance y in the next 10 second at the same acceleration. which of the following is true?
a)y =3x b)x=3y c)x=y d)y=2x

b) 180 m, a) y = 3x

Explanation:

1) Use constant acceleration equation:

x = x₀ + v₀ t + ½ at²

If we take down to be positive:

x = (0 m) + (0 m/s) (6 s) + ½ (9.8 m/s²) (6 s)²

x ≈ 180 m

2) The first distance covered is:

x = x₀ + v₀ t + ½ at²

x = (0) + (0) (10) + ½ a(10)²

x = 50a

The velocity it reaches after this is:

v = at + v₀

v = a(10) + (0)

v = 10a

The second distance covered is:

x = x₀ + v₀ t + ½ at²

y = x₀ + (10a) t + ½ at²

y = (0) + (10a) (10) + ½ a(10)²

y = 150a

Therefore:

y = 3x

another example of kinetic energy would be,

kinetic energy   >     moving energy

answer   >   letter choice (c),   a hammer falling off a table.

hope that !                                         : )