Answer:
88.18 W
Explanation:
The weight of the boy is given as 108 lb
Change to kg =108*0.453592= 48.988 kg = 49 kg
The slope is given as 6% , change it to degrees as
6/100 =0.06
tan⁻(0.06)= 3.43°
The boy is travelling at a constant speed up the slope = 7mi/hr
Change 7 mi/h to m/s
7*0.44704 =3.13 m/s
Formula for power P=F*v where
P=power output
F=force
v=velocity
Finding force
F=m*g*sin 3.43°
F=49*9.81*sin 3.43° =28.17
Finding the power out
P=28.17*3.13 =88.18 W
Answer:
1. 
2. 
Explanation:
1.
Given:
- height of the window pane,

- width of the window pane,

- thickness of the pane,

- thermal conductivity of the glass pane,

- temperature of the inner surface,

- temperature of the outer surface,

<u>According to the Fourier's law the rate of heat transfer is given as:</u>

here:
A = area through which the heat transfer occurs = 
dT = temperature difference across the thickness of the surface = 
dx = t = thickness normal to the surface = 


2.
- air spacing between two glass panes,

- area of each glass pane,

- thermal conductivity of air,

- temperature difference between the surfaces,

<u>Assuming layered transfer of heat through the air and the air between the glasses is always still:</u>



Answer:
Here are 2 sense i cant find 4
Explanation:
Levers are used to multiply force, In other words, using a lever gives you greater force or power than the effort you put in.
In a lever, if the distance from the effort to the fulcrum is longer than the distance from the load to the fulcrum, this gives a greater mechanical advantage.