It really doesn't matter how long the flight of stairs is. What we really need to know is how much height Mary gained, straight up. We don't know that. If we knew the height then the total amount of work she did would be 87 x the height in meters. The unit is joules. Then the power she delivered would be that number divided by the six seconds and that unit is watts.
By the way ... it's troubling that Mary's weight is only about 20 pounds. It's doubtful that such a tiny creature could run up a flight of stairs.
Answer:
<h2>The answer is 4 s</h2>
Explanation:
The time taken can be found by using the formula

where
d is the distance
v is the velocity
From the question we have

We have the final answer as
<h3>4 s</h3>
Hope this helps you
Answer: 1100 W
Explanation:
Input power = 220(5) = 1100 W
The transformer will step up/down voltage, but will also step down/up current.
Neglecting hysteresis and other minor losses, the power will remain the same.
Explanation:
is this a question????...
Explanation:
Initial speed of the rocket, u = 0
Acceleration of the rocket, 
Time taken, t = 3.39 s
Let v is the final velocity of the rocket when it runs out of fuels. Using the equation of kinematics as :

Let x is the initial position of the rocket. Using third equation of kinematics as :


Let
is the position at the maximum height. Again using equation of motion as :

Now
and v and u will interchange



x = 524.14 meters
Hence, this is the required solution.