Gear because each spike is a wedge shape that adds a mechanical advatage
Answer:
20.2 seconds
Explanation:
The airplane (and therefore the crate) initially has no vertical velocity, so v₀ = 0 m/s.
The crate is in free fall, so a = -9.8 m/s².
The crate falls downward, so Δx = -2000 m.
Find: t, the time it takes for the crate to land.
Δx = v₀ t + ½ at²
-2000 m = (0 m/s) t + ½ (-9.8 m/s²) t²
t = 20.2 s
It takes 20.2 seconds for the crate to land.
Answer:
the Princess in "St. George and the Dragon"
Answer:
<h3>13,976.23Joules</h3>
Explanation:
Workdone by the rope is expressed using the formula;
W = Fd sin(theta)
F is the tension in the rope = 180
d is the displacement = 300m
theta is the angle of inclination = 15°
Substitute the given parameters into the formula;
W = 180(300)sin15
W = 54000sin 15
W = 13,976.23
Hence the workdone by the rope is 13,976.23Joules
Answer:
Explanation:
a ) Entropy change dS = dQ/T
= mcdT /T
Integrating both sides
S₂ - S₁ = - mclnT₂ /T₁
= - .5 X 4200 ln (85+273) /( 20 + 273 )
.5 X 4200 ln 358/ 293
= - 417.6 J/K
Entropy change will be negative as heat is lost by the system .
b ) Sine there is no change in the temperature of air , This heat will enter air at temperature ( 20+ 273) K = 293 K
Heat entering air
= .5 x 4200 x 65
= 136500 J
Change in entropy
136500 / 293 ( room temperature is constant at 293k
= + 465.87 J/K
Entropy change will be positive as heat is gained by the system .
Total change in the entropy of the system (tea + air )
= +465.87 - 417.6
= 48.27 J/K
Entropy change will be negative as heat is lost by the system .
