Arock is dropped from the top of a vertical cliff and takes 3 s to reach the ground below the cliff. a second rock is thrown vertically from the top of the cliff, and it takes this rock 2 s to reach the ground below the cliff from the time it is released. with what velocity was the second rock thrown, assuming no air resistance?

The rock is thrown with a velocity equal to 12.25

Explanation:

Steps

Find the vertical distance from the first scenario given.Use the vertical distance(s) from the first scenario, to solve for the velocity in the second scenario.

Scenario One:

s =

where s = distance, g = 9.81, t = time

This gives us s = 44.1m

Scenario Two:

From Newton's equation of motion, we have

where a = acceleration due to gravity ( 9.8m/s^2)

          s = displacement of the rock equal to 44.1m

          t = time taken to complete this downward motion, equal to 2 seconds

         u = initial velocity at which the rock is thrown vertically

Therefore, substituting the  above into Newton's equation gives

44.1m = 2u + 0.5(-9.8 x )

After simplifying, we get

44.1m = 2u +

2u = 44.1 - 19.6, Therefore, u = 12.25

Note:

In a vertical velocity situation, when an object is dropped, the initial velocity is zero(0) when in a free fall because it has left contact with whatever held it. But when it is thrown, it has the exact same initial speed in free fall as it did before it was released.

answer and explanation;

composition refers to both the types of minerals within a rock and the overall chemical makeup of the rock while texture refers to the size and arrangement of the minerals or grains that make up a rock. both composition and texture can be used to classify rocks, such as igneous rocks. texture describes how the rock became solid or crystallized from liquid, melted rock. composition of a rock describes the minerals that make up a particular rock.

If football was tossed in air without gravity or friction the ball would go into space