Answer: 2.73m/s
Explanation:
Potential energy of the water is turned into kinetic energy
mgd = mv^2/2
Where m = mass of water
g = acceleration due to gravity = 9.81m/s^2
d = depth of the water = 0.38m
v = velocity of leaking water
m × 9.81 × 0.38 = mv^2/
eliminate m on both sides and multiply through by 2
7.4456 = v^2
v = sqrt(7.4456)
v = 2.73m/s
The cooler the temp of the star the star would appear to glisten a red. if the star is warmer the star would be a light blue or blue. An example would be the tiny red dwarf stars. they only have 7% of the suns heat so they appear red.
Answer:
C
Explanation:
During an investigation you want to investigate different variables.
Complete question is;
Shoveling snow can be extremely taxing since the arms have such a low efficiency in this activity. Suppose a person shoveling a sidewalk metabolizes food at the rate of 800 W. (The efficiency of a person shoveling is 3%.)
(a) What is her useful power output? (b) How long will it take her to lift 3000 kg of snow 1.20 m? (This could be the amount of heavy snow on 20 m of footpath.) (c) How much waste heat transfer in kilojoules will she generate in the process?
Answer:
A) P_out = 24 W
B) t = 1470 s
C) Q = 1140.72 KJ
Explanation:
We are given;
Input Power; P_in = 800 W
Efficiency; η = 3% = 0.03
A) Formula for efficiency is;
η = P_out/P_in
Making P_out the subject, we have;
P_out = η•P_in
P_out = 0.03 × 800
P_out = 24 W
B) We know that;
Power = work done/time taken
Thus;
P_out = mgh/t
We are given;
m = 3000 kg
h = 1.20 m
Thus, time is;
t = (3000 × 9.8 × 1.2)/24
t = 1470 s
C) amount of heat wasted is calculated from;
Q = (P_in - P_out)t
Q = (800 - 24) × 1470
Q = 1,140,720 J
Q = 1140.72 KJ
Answer:
The density of salt water is more than that of density of fresh water, so so salt and fresh water makes a difference in floating of ships.
