Question

Multiple-Concept Example 6 reviews the concepts that play a role in this problem. A diver springs upward with an initial speed of 2.22 m/s from a 3.0-m board. (a) Find the velocity with which he strikes the water. [Hint: When the diver reaches the water, his displacement is y = -3.0 m (measured from the board), assuming that the downward direction is chosen as the negative direction.] (b) What is the highest point he reaches above the water?

Answer 1

Part a)

`v_f = 7.99 m/s`

Part b)

`y = 3.25 m`

Step-by-step explanation:

Part a)

Since the diver is moving under gravity

so here its acceleration due to gravity will be uniform throughout the motion

so here we will have

`v_f^2 - v_i^2 = 2 a y`

here we have

`v_i = 2.22 m/s`

`y = -3 m`

`v_f^2 - (2.22)^2 = 2(-9.81)(-3)`

`v_f = 7.99 m/s`

Part b)

at highest point of his motion the final speed will be zero

so we will have

`v_f^2 - v_i^2 = 2 a (\Delta y)`

`0 - 2.22^2 = 2(-9.81)(y - 3)`

`y = 3.25 m`