While standing at the edge of the roof of a building, you throw a stone upward with an initial speed of 6.25 m/s. The stone subsequently falls to the ground, which is 13.3 m below the point where the stone leaves your hand. At what speed does the stone impact the ground? How much time is the stone in the air? Ignore air resistance and take g = 9.8 m/s2.

1.) 17.3 m/s

2.) 1.8 s

Explanation:

Given that While standing at the edge of the roof of a building, you throw a stone upward with an initial speed of 6.25 m/s.

The maximum height will be calculated by using third equation of motion

At maximum height, V = 0

V^2 = U^2 - 2gH

0 = 6.25^2 - 2 × 9.8 × H

39.06 = 19.6H

H = 39.06 / 19.6

H = 1.993m

The stone subsequently falls to the ground, which is 13.3 m below the point where the stone leaves your hand. At what speed does the stone impact the ground?

Using the same formula again.

Where the height = 13.3 + 1.993

Height = 15.29m

Substitutes the height into the third equation of motion

V^2 = U^2 + 2gH

U = 0

V^2 = 0 + 2 × 9.8 × 15.29

V^2 = 299.74

V = sqrt ( 299.74 )

V = 17.3 m/s

How much time is the stone in the air? Ignore air resistance and take g = 9.8 m/s2.

Using the second equation of motion formula

H = Ut + 1/2gt^2

U = 0

15.29 = 1/2 × 9.8 × t^2

15.29 = 4.9t^2

t^2 = 15.29 / 4.9

t^2 = 3.120

t = sqrt ( 3.120 )

t = 1.766 s

Therefore, the stone is on air for 1.8s approximately.

1 - wave length

2 - amplitude

3 - crest

4 - trough

explanation:

duh.

note: the given question is incomplete.

complete question is given below.

which is an example of kinetic energy?

a. the energy stored in ethanol  

b. a hockey puck sliding across the ice  

c. a compressed spring  

d. a ball sitting at the top of a ramp

solution: the kinetic energy is the energy posses by the virtue of the motion of the object.

in the given options, a, c and d are the example of potential energy because it is the energy posses by the virtue of the rest of the object. but option b has the kinetic energy as the object is in motion.

hence, a hockey puck sliding across the ice   is the apex example of kinetic energy.

so, the option (b) a hockey puck sliding across the ice   is the correct option.