Answer:
80%
Explanation:
Efficiency = Power output / Power input × 100 %
To calculate efficiency we need to find power output of electric pump.
We can use,
Work done = Energy change
Work done per second = Energy change per second
Work done per second = Power
Therefore, Power = Energy change per second
= Change in potential energy of water per second
=mgh / t
= 200× 10×6 / 10
= 1200 W = 1.2 kW
Now use the first equation to find efficiency,
Efficiency = 
× 100%
= 80 %
Force is defined as the rate of change of momentum.
The initial amount of momentum is
because water stops when it hit the wall total change of momentum must be
.
Now let's calculate the force.
We need to find
. This is the amount of water hiting the wall per second.
Our final formula would be:
And now we can calculate the answer:
Answer:
The minimum total speed is 11.2km/s
Explanation:
We are been asked to find the escape velocity.
Escape velocity is defined as the minimum initial velocity that will take a body(projectile)away above the surface of a planet(earth) when it's projected vertically upwards.
The formula to calculate the escape velocity is Ve = √2gR
For the earth g = 9.8m/s2 , R = 6.4*10^6
Substituting into the equation Ve = √2*9.8*6.4*10^6 = 11.2*10^3m/s
=11.2km/s
Answer:
20 meters.
Explanation:
Since it went 100 meters in 10 seconds, that means it is going 10 meters per second. In 2 seconds, it must have gone 20 meters, if the speed is constant.
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