Answer:
13 u2 = 0 – (2 × –2 m/s2 × 6 m) = 24, u = 4.9 m
Explanation:
One example is that when their food catches fire in a cooking pot or pan, it is advisable to smother the fire by covering the fire with a blanket rather than douse the fire with water. DOeing the later will only aggravate the fire. Knowledge of basic science dictates that oil and water are immiscible liquids the oil will continue to burn even as the water is poured into the oil. More so, as the water violently evaporates due to the heat, it spreads the burning oil and hence spreads the fire.
Complete question is;
a. Two equal sized and shaped spheres are dropped from a tall building. Sphere 1 is hollow and has a mass of 1.0 kg. Sphere 2 is filled with lead and has a mass of 9.0 kg. If the terminal speed of Sphere 1 is 6.0 m/s, the terminal speed of Sphere 2 will be?
b. The cross sectional area of Sphere 2 is increased to 3 times the cross sectional area of Sphere 1. The masses remain 1.0 kg and 9.0 kg, The terminal speed (in m/s) of Sphere 2 will now be
Answer:
A) V_t = 18 m/s
B) V_t = 10.39 m/s
Explanation:
Formula for terminal speed is given by;
V_t = √(2mg/(DρA))
Where;
m is mass
g is acceleration due to gravity
D is drag coefficient
ρ is density
A is Area of object
A) Now, for sphere 1,we have;
m = 1 kg
V_t = 6 m/s
g = 9.81 m/s²
Now, making D the subject, we have;
D = 2mg/((V_t)²ρA))
D = (2 × 1 × 9.81)/(6² × ρA)
D = 0.545/(ρA)
For sphere 2, we have mass = 9 kg
Thus;
V_t = √[2 × 9 × 9.81/(0.545/(ρA) × ρA))]
V_t = 18 m/s
B) We are told that The cross sectional area of Sphere 2 is increased to 3 times the cross sectional area of Sphere 1.
Thus;
Area of sphere 2 = 3A
Thus;
V_t = √[2 × 9 × 9.81/(0.545/(ρA) × ρ × 3A))]
V_t = 10.39 m/s
The work needed to pump the water would have the units of Joules or Pa*m^3. From here, this would be a hint that you only multiply the hyraulic pressure and its volume.
Hydraulic pressure = density*gravity*height = 1000*9.8*3.1 = 30,411 Pa
Volume = 21*14*3.1 = 911.4 m^3
Work = 30,411*911.4 = 27,716,585.4 J = 27.72 MJ
The answer is aluminum foil is homogeneous