Answer:
30m/s
Explanation:
Suppose there's no friction between the office chair and the floor. The only thing that impact the motion of the boy is the ejected carbon dioxide. We can apply the law of momentum conservation to find the his (the boy, the chair and the empty extinguisher) after the extinguisher is emptied.
Before the ejects, the system momentum is 0, due to at rest and no speed
After the ejects, momentum of the carbon dioxide is
9*20 = 180 kg m/s
The momentum of his is then
P + 180 = 0
P = -180
MV = -180
(26 + 16 + 18)V = - 180
V = -180/(26 + 16 + 18) = -30 m/s
So he would have a speed of 30m/s in the opposite of the ejected carbon dioxide direction
The direction of the electrical force is dependent upon whether the charged objects are charged with like charge or opposite charge and upon their spatial orientation. By knowing the type of charge on the two objects, the direction of the force on either one of them can be determined with a little reasoning.
<span>137200000 watts
or 137200 kilowatts
The formula for power is
P= dhrg
Where
P = Power in watts
d = density of water (~1000 kg/m^3)
h = height in meters
r = flow rate in cubic meters per second,
g = acceleration due to gravity of 9.8 m/s^2,
Plugging in the known values, we get
P = 1000 kg/m^3 * 80 m * 175 m^3/s * 9.8 m/s^2
P = 80000 kg/m^2 * 175 m^3/s * 9.8 m/s^2
P = 14000000 kg m/s * 9.8 m/s^2
P = 137200000 kg m^2/s^3
P = 137200000 watts
or 137200 kilowatts
The above figure assumes 100% efficiency which is impossible. A good efficiency would be 90% so the actual power available would be close to 0.90 * 137200 = 123480 kilowatts</span>
Answer:
the answer is option f:the box is so heavy...
Answer:
Explanation:
v = u + at
Let Up be the positive direction
v(2) = 24 + (-9.8)(2) = 4.4 m/s Positive result means Upward
v(3) = 24 + (-9.8)(3) = -5.4 m/s Negative result means Downward