Answer:
F = 1094.4 N
Explanation:
From impulse - momentum theorem, we now that ;
Impulse = momentum
Where;
Formula for impulse = force (F) × time(t)
Momentum = mass(m) × velocity(v)
Now, we are given;
Mass of swimmer; m = 72 kg
Speed; v = 3.8 m/s
Time; t = 0.25 s
Thus;
F × t = mv
F = mv/t
F = (72 × 3.8)/0.25
F = 1094.4 N
This value of force is the magnitude of the average horizontal force by diver on the raft.
Explanation:
- A thermometer does measure the temperature of a body and not the heat. It is known that temperature is a measure of average kinetic energy.
Therefore, the statement a thermometer measures the average kinetic energy of a substance is correct.
- Heat is a form of energy as it can make a colder substance become hot and it moves from one place to another. Thus, the statement heat is a form of energy is correct.
- Also, heat flows from hotter substance to colder substance. Hence, the statement heat flows from a colder substance to a hotter substance is correct.
- Convection is a property of fluids or gases which makes less denser (hot) material to rise and more denser (colder) material to sink.
Therefore, the statement convection occurs only in liquids and gases is correct.
- All substances radiate heat is an incorrect statement. For example, a thermos bottle does not radiate heat.
- Temperature of our body is about 98.4 degree celsius and hence we can conclude that the statement our body temperature is always equal to the temperature around us is incorrect.
3.51 × 10^-7m
Explanation:
Refractive index = wavelength of the light in air ÷ wavelength in the medium
wavelength in the medium = wavelength of the light in air ÷ refractive index
= 5.4 * 10^-7 ÷ 1.54
= 3.51 × 10^-7m
That's called "<em>Geothermal</em>" energy.
"Geo ..." always means something about the Earth.
"Thermal ..." always means something about heat.
Geothermal energy is used in places where there's a lot of heat that's not too far under the ground, like in places above ancient volcanos.
The system is built with pipes running deep down into the ground and then back up again, and then running water is pumped through the pipes. The water picks up heat from down under and brings the heat up to the surface, where it can be used to heat homes and buildings, and turn steam turbines to generate electricity.
Geothermal is the MAIN source of energy in Iceland.
<h2>
Answer:53.63
</h2>
Explanation:
The equations of motion used in this question is 
When a object is projected horizontally from a sufficiently height,the x-component of acceleration remains zero because there is no force that drags the object in x direction.
But,due to gravity,the object accelerates downward at a rate of 
.
In X-Direction,
Given that initial velocity=
=
Using ,
In Y-Direction,
Given that initial velocity==
Using ,
