An alarm clock is dropped off the edge of a tall building. You, standing directly under it, hear a tone of 1350 Hz coming from the clock at the instant it hits the ground. Since you know the building is 25 m tall, you can find out what the frequency of the alarm would be if you had just held it in your hands. What would that frequency be

the frequency clock would be 1262.85 Hz

Explanation:

Given data;

height of building h = 25 m

from the third equation of motion;

v² = u² + 2as

Since the Alarm clock falls with an acceleration equal to the acceleration due to gravity; a = g = 9.81 m/s²

initial velocity u = 0

so we substitute our values into the kinematic equation

v² = (0)² + 2 × 9.81 × 25

v² = 490.5

v = √490.5

v = 22.1472 m/s

Now, since the alarm clock is moving both I am stationary;

my velocity will be zero.

so Frequency of the alarm clock will be;

f' = [ (v - ) / ( v + ) ] × f

we know that; speed of sound is 343 m/s, so v = 343 m/s, is 22.1472 m/s, f is 1350 Hz,  is 0 m/s

so we substitute the values into the equation

f' = [ (343 - 22.142 ) / ( 343 + 0 ) ] × 1350

f' = [ 320.858 / 343 ] × 1350

f' = 0.935446 × 1350

f' = 1262.85 Hz

Therefore, the frequency clock would be 1262.85 Hz

  1.the balanced   chemical equation is as below

cu +   2 ag(no)₃ → cu(no₃)₂   +2 ag

2.the   much silver   produced   is   50.9 g

step 1: find the   moles of cu

moles =   mass÷   molar mass

  from periodic table the molar mass of cu = 63.5 g/mol

moles is therefore = 15.00 g÷ 63.5 g/mol = 0.236   moles

step 2: use the mole ratio to determine the   moles of ag

from equation above   cu: ag   is 1: 2

therefore the moles of ag   =0.236   moles   x 2/1 =0.472   moles

step 3: find the mass   of ag

mass = moles x molar mass

from periodic table   the molar mass of ag =107.87 g/mol

mass   = 0.472   moles x 107.87 g/mol = 50.9 g

3.   the   much   silver   collected worth is   1.797 oz

  convert   50.9 g   to oz

that is   1 gram = 0.0353 oz

          50.9 grams =?   oz

by cross multiplication

={(50.9 grams x 0.0353 oz) / 1   gram}   =1.797 oz