Answer:
a= -0.86 m/s²
The negative sign shows that ball down the ground or moving down
Explanation:
Vf² - Vo² = 2gS
where
Vf = velocity of clay as it hits the ground
Vo = initial velocity of clay = 0
g = acceleration due to gravity = 9.8 m/sec^2 (constant)
S = distance travelled by clay = 15 m
Substituting appropriate values,
Vf² - 0 = 2(9.8)(15)
Vf = 17.15 m/sec.
Formula to use is,
V - Vf = aT
where
V = velocity of clay when it stops = 0
Vf = 17.15 m/sec (as determined above)
a = acceleration
T = 20 ms
Put the values to find acceleration
a=(V-Vf)/T
a=(0-17.15)/20
a= -0.86 m/s²
The negative sign shows that ball down the ground
If both waves have the same wavelength, then the amplitude of
their sum could be anything between 1 cm and 9 cm, depending
on the phase angle between them.
If the waves have different wavelengths, then the resultant is a beat
with an amplitude of 9 cm.
Answer:
1.95m/s
Explanation:
Please view the attached file for the detailed solution.
The following were the conversion factors used in order to express all quatities in SI units:

It all comes to the doppler effect, the red shift means that the galaxy is moving away from us. The redshift is a result from the doppler effect, so as the galaxy moves away the wavelength expands, increasing the wavelength which responds to the red light.