Can you please show each step preparation, plan, solve and check. Thanks you Pro

Question

Can you please show each step preparation, plan, solve and check. Thanks you
Problem 4 Chapter 14: A flowerpot is knocked off a window ledge from a height da 25m above the sidewalk. It falls toward an unsuspecting child of height h 1.5m who is standing below. Assume the child requires 0.30 seconds to respond to the warning. a) How close to the sidewalk can the flowerpot fall before it is too late for a warning shouted from the window to reach the man in time? b) Suppose the shout is performed by a man practicing his opera cords, and he is in an elevator, which is at the height of the window. He is the same distance from the child as the window. He wants to startle the child into action with a loud low-pitch A2 (110 Hz). Unfortunately, his elevator is also ascending at 4 m/s. The child has a hearing difficulty and can't hear below 100Hz. Will the child respond?

Explanation / Answer

pot have to fall 23.5m to hit the child.

time taken to fall,

d = u t + a t^2 /2

23.5 = 0 + 9.8 t^2 /2

t = 2.19 sec

distance fallen in (2.19 - 0.30) s = 1.89s

d1 = 0 + 9.8(1.89^2)/2 = 17.5 m

Mimimum safe distance = d - d1 = 6 m .......Ans

(B) Applying doppler effect,

f = f0 (v + vr) / (v + vs)

v = velocity of sound = 343 m/s

vr = velocity of reciver = 0

vs = velocity of source = 4m/s

f = (110) (343) / (343 + 4) = 108.7 Hz that is greater than 100 Hz

hence child will respond.

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