Answer:
133.62 kmh.
Explanation:
Time provided = 3.25 hours.
Distance to be covered 300 km
Times spent in first 100 km = 1 hour
Time spent in next 43 km
= 43 / 40 = 1.075 hours
Total time spent = 2.075 hours
Total distance covered = 143 km
Distance remaining = 300 - 143
=157 km .
Time remaining = 3.25 - 2.075
= 1.175
Speed required = Distance remaining / time remaining
= 157 / 1.175
= 133.62 kmh.
Answer:
Induced emf will be 0.468 volt
Explanation:
We have given diameter of wire d = 15.3 cm
So radius 
So area 
Change in magnetic field dB = 0.26 - 0.77 = -0.51 T
Time for change in magnetic field dt = 0.26 sec
We know that emf is given by 
Answer:
Geothermal energy can heat, cool, and generate electricity: Geothermal energy can be used in different ways depending on the resource and technology chosen—heating and cooling buildings through geothermal heat pumps, generating electricity through geothermal power plants, and heating structures through direct-use
Explanation:
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
One way that the world's ocean affects weather and climate is by playing an important role in keeping our planet warm. ... The ocean doesn't just store solar radiation; it also helps to distribute heat around the globe. When water molecules are heated, they exchange freely with the air in a process called evaporation.