Question

On a hot summer day in the state of Washington while kayaking, I saw several swimmers jump from a railroad bridge into the Snohomish River below. The swimmers stepped off the bridge, and I estimated that they hit the water 2.00 s later. You may want to review (Pages 44 - 49)

Answer 1

Given

t = 2 seconds

Here, we need to use kinematics,

(a) h = 1/2at²

here a = g = 9.8 m/s²

h = 1/2 * 9.8 * 2²

h = 19.6 m

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(b) v² - u² = 2gh

assuming, the swimmer jumps from rest, u = 0

so,

v = sqrt (2gh)

v = sqrt ( 2 * 9.8 * 19.6)

v = 19.6 m/s