Answer:
A. 39.2 m/s
B. 78.4 m
Explanation:
Data obtained from the question include:
Time (t) = 4 s
Acceleration due to gravity (g) = 9.8 m/s²
A. Determination of the brick's velocity.
Time (t) = 4 s
Acceleration due to gravity (g) = 9.8 m/s²
Velocity (v) =?
v = gt
v = 4 × 9.8
v = 39.2 m/s
Thus, the brick's velocity after 4 s is 39.2 m/s
B. Determination of how far the brick fall in 4 s.
Time (t) = 4 s
Acceleration due to gravity (g) = 9.8 m/s²
Height (h) =?
h = ½gt²
h = ½ × 9.8 × 4²
h = 4.9 × 16
h = 78.4 m
Thus, the brick fall 78.4 m during the time.
F=ma
m=total mass = 2300kg+2500kg=4800
F=18000N
a=?
a=F/m
a=18000/4800
a=3.8m/s^2
Final answer
Answer:
The distance between the earth and the star is increasing.
Explanation:
When we observe an object and its electromagnetic radiation has been displaced to blue, it means that it is getting closer to us, causing the light waves it emits to get closer together and its wavelength to decrease towards blue, this is knowm as blueshift.
On the contrary, when an object is rapidly moving away from us, the light waves or electromagnetic radiation it emits have been stretched from their normal wavelength to a longer wavelength, towards the red part of the spectrum. This is known as redshift.
This phenomenon of changes in wavelength and frequency due to movement (whether the source approaches or moves away) is described by the Doppler effect.
So for this case because the light we perceive from the star has moved to the red part of the visible spectrum, we can conclude that it is moving away from the earth, and that the distance between the star and the earth is increasing.
Answer:
see explanation below
Explanation:
Given that,
500°C
= 25°C
d = 0.2m
L = 10mm = 0.01m
U₀ = 2m/s
Calculate average temperature
262.5 + 273
= 535.5K
From properties of air table A-4 corresponding to 
= 535.5K 
k = 43.9 × 10⁻³W/m.k
v = 47.57 × 10⁻⁶ m²/s
A)
Number for the first strips is equal to
Calculating heat transfer coefficient from the first strip
The rate of convection heat transfer from the first strip is
The rate of convection heat transfer from the fifth trip is equal to
Calculating 
The rate of convection heat transfer from the tenth strip is
Calculating
Calculating the rate of convection heat transfer from the tenth strip
The rate of convection heat transfer from 25th strip is equal to
Calculating 
Calculating 
Calculating the rate of convection heat transfer from the tenth strip
