Answer:
38.8 m/s
Explanation:
Force F(x) = 6 - 2x + 6x²
work


W = mv²/2=7v²/2 = 3.5v² = 5261
v = 38.8 m/s
The power developed by the student is 756.9 J/s and remains the same if the student takes the same time to climb the stairs when climbing it in two's and three's.
<h3>What is power?</h3>
Power is the rate at work is done.
- Power = work done/time
- work done = mass × acceleration due to gravity × height
Work done = 65.5 × 10 × (18 × 0.165) = 1945.35 J
Power = 1945.35/2.57 = 756.9 J/s
If the student climbed the steps in two or three at a time, the power does not change if the time remains the same.
- Time required = Energy/ power
The time required to convert the Big Mac meal from McDonalds = 4 853 440/756.9
Time required = 6412.26 seconds
Therefore, from the power developed by the student, it will take him 6412.26 seconds to convert all the energy in a Big Mac meal.
Learn more about power at: brainly.com/question/1634438
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Answer:
3.64 m
Explanation:
m = Mass of object = 70 kg
Kinetic energy of the object = 2500 J
g = Acceleration due to gravity = 
h = Height from which the object is dropped
Kinetic energy is given by

From conservation of energy we get kinetic energy equal to potential energy.

The object was released from a height of 3.64 m.
1) 260 km/h
Let's use the following convention:
positive x-direction = east
positive y-direction = north
Here we have to find the north component of the velocity's airplane, which means we have to find its y-component.
We can use the formula:

where
v = 750 km/h is the magnitude of the plane's velocity
is the angle between the direction of the plane and the positive x-axis
Substituting,

2)
north of east
In order to find the direction of flight, we have to consider that the vector representing the displacement of the plane is the hypothenuse of a right triangle, of which the displacements along the east and north direction are the sides.
Therefore, we have
is the displacement towards east
is the displacement towards north
Therefore, the angle that gives the direction is given by

And substituting,

and this angle is measured north of east.
Time = (distance) / (speed)
Distance = 3,000 km = 3,000,000 meters
Speed = 200 m/s
Time = (3,000,000 m) / (200 m/s)
Time = <em>15,000 seconds</em>
That's 4 hours 10 minutes