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labwork [276]
3 years ago
10

An airplane flies 21 km in 30 minutes. What is its average speed in kilometers per hour?

Physics
2 answers:
Katena32 [7]3 years ago
8 0

Average speed = (distance covered) / (time to cover the distance)

Average speed = (21 km) / (1/2 hour)

Average speed = (21/0.5) (km/hour)

Average speed = 42 km/hr

A very slow airplane !  Maybe an ultralight, a motorized hang-glider, etc.

Citrus2011 [14]3 years ago
7 0
30 minutes is 1/2 of an hour.

So if you just multiplied 21×2, you would get you answer.
The answer is:
42 kilometers per hour
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3 years ago
A tank has the shape of an inverted circular cone with height 16m and base radius 3m. The tank is filled with water to a height
rewona [7]

Answer:

W=17085KJ

Explanation:

From the question we are told that:

Height H=16m

Radius R=3

Height of water H_w=9m

Gravity g=9.8m/s

Density of water \rho=1000kg/m^3

Generally the equation for Volume of water is mathematically given by

 dv=\pi*r^2dy

 dv=\frac{\piR^2}{H^2}(H-y)^2dy

Where

   y is a random height taken to define dv

Generally the equation for Work done to pump water is mathematically given by

 dw=(pdv)g (H-y)

Substituting dv

 dw=(p(=\frac{\piR^2}{H^2}(H-y)^2dy))g (H-y)

 dw=\frac{\rho*g*R^2}{H^2}(H-y)^3dy

Therefore

 W=\int dw

 W=\int(\frac{\rho*g*R^2}{H^2}(H-y)^3)dy

 W=\rho*g*R^2}{H^2}\int((H-y)^3)dy)

 W=\frac{1000*9.8*3.142*3^2}{9^2}[((9-y)^3)}^9_0

 W=3420.84*0.25[2401-65536]

 W=17084965.5J

 W=17085KJ

 

'

'

4 0
3 years ago
Help? Please? Thanks!
Katena32 [7]
1,3 and 5 are the answers 
5 0
3 years ago
Suzette had prepared the graph below to add to her lab
Charra [1.4K]

Answer:

A title

Explanation:

Because this is middle school.

4 0
3 years ago
Read 2 more answers
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