Answer:
374 N
Explanation:
N = normal force acting on the skier
m = mass of the skier = 82.5
From the force diagram, force equation perpendicular to the slope is given as
N = mg Cos18.7
μ = Coefficient of friction = 0.150
frictional force is given as
f = μN
f = μmg Cos18.7
F = force applied by the rope
Force equation parallel to the slope is given as
F - f - mg Sin18.7 = 0
F - μmg Cos18.7 - mg Sin18.7 = 0
F = μmg Cos18.7 + mg Sin18.7
F = (0.150 x 82.5 x 9.8) Cos18.7 + (82.5 x 9.8) Sin18.7
F = 374 N
Correct question is;
A thermal tap used in a certain apparatus consists of a silica rod which fits tightly inside an aluminium tube whose internal diameter is 8mm at 0°C.When the temperature is raised ,the fits is no longer exact. Calculate what change in temperature is necessary to produce a channel whose cross-sectional is equal to that of the tube of 1mm. (linear expansivity of silica = 8 × 10^(-6) /K and linear expansivity of aluminium = 26 × 10^(-6) /K).
Answer:
ΔT = 268.67K
Explanation:
We are given;
d1 = 8mm
d2 = 1mm
At standard temperature and pressure conditions, the temperature is 273K.
Thus; Initial temperature; T1 = 273K,
Using the combined gas law, we have;
P1×V1/T1 = P2×V2/T2
The pressure is constant and so P1 = P2. They will cancel out in the combined gas law to give:
V1/T1 = V2/T2
Now, volume of the tube is given by the formula;V = Area × height = Ah
Thus;
V1 = (πd1²/4)h
V2 = (π(d2)²/4)h
Thus;
(πd1²/4)h/T1 = (π(d2)²/4)h/T2
π, h and 4 will cancel out to give;
d1²/T1 = (d2)²/T2
T2 = ((d2)² × T1)/d1²
T2 = (1² × T1)/8²
T2 = 273/64
T2 = 4.23K
Therefore, Change in temperature is; ΔT = T2 - T1
ΔT = 273 - 4.23
ΔT = 268.67K
Thus, the temperature decreased to 268.67K
Answer:
As per the fossil fuel records, magnetic field reversal does not impact living beings. It will take almost a century for the poles to complete the shift. Meanwhile, the earth is left with almost zero magnetic field.
Answer:
A. fuel mileage and longevity
Explanation:
For a person purchasing a car, car longevity is one of the main concern. They are also interested in many things such as maximum mileage and service life.
By properly monitoring and assessing few measures one can maintain the efficiency and longevity of the car. One such thing is by monitoring the liquid levels of the car. Certain liquids like the coolant or radiator water level should be well maintain in proper level in order to run the car economically.
Thus by doing this, one can optimize the car's longevity and the fuel mileage.
Hence the correct option is (A).
The result of the Mexican victory was that fallen defenders
became heroes to the cause of Texan independence.<span> The Battle of
the Alamo took place between February 23 and March 6, 1836 and became the
central episode of the Texas
Revolution . After this thirteen-day battle, the
Mexican troops of General President Antonio
Lopez de Santa Anna began an attack on San Antonio de
Bexar, the current San Antonio in Texas. The Battle of the Alamo fought the
army of Mexico against
a group of Texan rebels, mostly American settlers. More than four thousand
men from Santa Ana stood in front of
the Alamo Fort , the last stronghold of the rebels, which
barely reached 187. The Alamo was not a fortress prepared to withstand a siege.
It is believed that all the rebels of the Alamo died in the siege, but Santa
Anna came to lose up to about 900 men during the days that lasted the fight. However,
the worst result for Santa Ana was precisely the resistance that the Texan
rebels had in the Alamo, which fostered the fighting spirit of the Texans. A
few days later, on March 14, 1836, Texas became independent from Mexico and a
month later, Santa Ana was imprisoned.</span>
