Answer:
a)Work done by fireman= 2.15 Btu
b) Time t= 0.86 sec
Explanation:
Given that
Weight = 280 lbf
We know that 1 lbf = 4.44 N
so 280 lbf = 1245.5 N
Weight =1245.5 N
Height h = 60 ft
We know that
1 ft = 0.3048 m
So 60 ft = 18.28 m
h =18.28 m
Power = 3.5 hp
We know that
1 hp =0.74 KW
So 3.5 hp = 2.61 KW
Power = 2.61 KJ/s
So the work done by fireman = Weight x h
Now by putting the values
Work done by fireman= 1245.5 x 18.28 J
Work done by fireman= 2267.74 J
Work done by fireman= 2.26774 KJ
We know that 1 Btu= 1.05 KJ
So 2.266 KJ = 2.15 Btu
Work done by fireman= 2.15 Btu
We know that ,rate of work is called power.
Power x time = work
2.61 x t = 2.26
So t= 0.86 sec
Answer:
80×5×10=4000J
so therefore, work done on the body is 4000J
Answer:
For a body moving at a uniform velocity you can calculate the speed by dividing the distance traveled by the amount of time it took, for example one mile in 1/2 hour would give you 2 miles per hour. If the velocity is non-uniform all you can say is what the average speed is.
Answer:
c
Explanation:
It light wave will travel at speed of light and go faster in its wavelength
The period of the sound wave at the given frequency is determined as 0.00235 second.
<h3>
Period of the sound wave</h3>
The period of the sound wave at the given frequency is calculated as follows;
Period is reciprocal of frequency.
T = 1/f
T = 1/425
T = 0.00235 second
Thus, the period of the sound wave at the given frequency is determined as 0.00235 second.
Learn more about period here: brainly.com/question/10428039
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