Answer:
average acceleration is 1.365 × 
m/s²
Explanation:
given data
initila speed u = -32.2 m/s
final speed v = 21.6 m/s
time taken t = 0.00394 s
solution
we get here average acceleration that will be express as
v = u + at ..........................1
put here value and we get
21.6 = -32.2 + a × 0.00394
solve it we get
a = 1.365 × m/s²
so average acceleration is 1.365 × m/s²
The change in pitch of a train's horn as it passes while you are
standing still can be described by the Doppler effect, but that
doesn't explain it.
Answer:
A. The time taken for the car to stop is 3.14 secs
B. The initial velocity is 81.64 ft/s
Explanation:
Data obtained from the question include:
Acceleration (a) = 26ft/s2
Distance (s) = 256ft
Final velocity (V) = 0
Time (t) =?
Initial velocity (U) =?
A. Determination of the time taken for the car to stop.
Let us obtain an express for time (t)
Acceleration (a) = Velocity (V)/time(t)
a = V/t
Velocity (V) = distance (s) /time (t)
V = s/t
a = s/t^2
Cross multiply
a x t^2 = s
Divide both side by a
t^2 = s/a
Take the square root of both side
t = √(s/a)
Now we can obtain the time as follow
Acceleration (a) = 26ft/s2
Distance (s) = 256ft
Time (t) =..?
t = √(s/a)
t = √(256/26)
t = 3.14 secs
Therefore, the time taken for the car to stop is 3.14 secs
B. Determination of the initial speed of the car.
V = U + at
Final velocity (V) = 0
Deceleration (a) = –26ft/s2
Time (t) = 3.14 sec
Initial velocity (U) =.?
0 = U – 26x3.14
0 = U – 81.64
Collect like terms
U = 81.64 ft/s
Therefore, the initial velocity is 81.64 ft/s
Answer:
Statement 2 is wrong
Explanation:
To check the statements in this exercise, let's describe the main properties of electromagnetic waves. Let's describe the characteristics
* they are transverse waves
* formed by the oscillations of the electric and magnetic fields
* the speed of the wave is the speed of light
with these concepts let's review the final statements
1) True. Formed by the oscillation of the two fields
2) False. They are transverse waves
3) True. Can travel by vacuum as they are supported by oscillations of the electric and magnetic fields
4) True. They all have the same speed of light
Statement 2 is wrong
Answer:
Explanation:
Given:
temperature at the hotter end, 
temperature at the cooler end, 
length of rod through which the heat travels, 
cross-sectional area of rod, 
mass of ice melted at zero degree Celsius, 
time taken for the melting of ice, 
thermal conductivity k=?
By Fourier's Law of conduction we have:
......................................(1)
where:
=rate of heat transfer
dT= temperature difference across the length dx
Now, we need the total heat transfer according to the condition:
we know the latent heat of fusion of ice, 
Now the heat rate:
Now using eq,(1)
