S=d/t
30/0.75=40
Answer: 40km/h
Answer:
A. Using
Fl= ( v+vl/v+vz)fz
= (340+19/340+31) x 2020
= 1954.7Hz
Then to find the frequency of sound when reflected from the truck such that the driver becomes the listener
we use
F"= ( v+vz/v+vl) fz
= 340+31/340+19 x 2020
2087.5Hz
B to find the wavelength of sound we use
Wavelength= V+vl/ F"
= 340+31/2087.5= 0.18m
Efficiency η of a Carnot engine is defined to be:
<span>η = 1 - Tc / Th = (Th - Tc) / Th </span>
<span>where </span>
<span>Tc is the absolute temperature of the cold reservoir, and </span>
<span>Th is the absolute temperature of the hot reservoir. </span>
<span>In this case, given is η=22% and Th - Tc = 75K </span>
<span>Notice that although temperature difference is given in °C it has same numerical value in Kelvins because magnitude of the degree Celsius is exactly equal to that of the Kelvin (the difference between two scales is only in their starting points). </span>
<span>Th = (Th - Tc) / η </span>
<span>Th = 75 / 0.22 = 341 K (rounded to closest number) </span>
<span>Tc = Th - 75 = 266 K </span>
<span>Lower temperature is Tc = 266 K </span>
<span>Higher temperature is Th = 341 K</span>
Answer:
960 m
Explanation:
Given that,
- Speed = 120 m/s
- Time taken = 4 minutes
We have to find the distance covered.
Firstly, let's convert time in seconds.
→ 1 minute = 60 seconds
→ 4 minutes = (4 × 60) seconds
→ 4 minutes = 240 seconds
Now, we know that,
→ Distance = Speed × Time
→ Distance = (4 × 240) m
→ Distance = 960 m
Therefore, distance covered is 960 m.