Answer:
4miles/hour
Explanation:
the solution for this question requires that the quantities are converted to the appropriate units as required by the question.
Rate in miles per hour = distance in miles / time in hour
to convert 12 minutes to hours; recall that 60 minutes make 1 hour
12 minutes to hour = 12/60 = 0.2hr
to convert 4224 feet to miles; recall 5280 feet is equivalent to 1 mile
4224 feet to miles = 4224/5280 = 0.8 miles
∴ rate = 0.8 / 0.2
rate = 4 miles per hour
the constant rate in miles per hour = 4 miles/hour
The final vertical velocity of the skydiver at 50.8 m of fall is 31.56 m/s.
<h3>
Time of motion of the girl</h3>
The time of motion of the girl is calculated as follows;
h = vt + ¹/₂gt²
where;
- v is initial vertical velocity = 0
- t is time of motion
- g is acceleration due to gravity
Substitute the given parameters and solve for time of motion;
50.8 = 0 + ¹/₂(9.8)t²
2(50.8) = 9.8t²
101.6 = 9.8t²
t² = 101.6/9.8
t² = 10.367
t = √10.367
t = 3.22 seconds
<h3>Final vertical velocity of the skydiver</h3>
vf = vi + gt
where;
vi is the initial vertical velocity = 0
vf = 0 + 9.8(3.22)
vf = 31.56 m/s
Thus, the final vertical velocity of the skydiver at 50.8 m of fall is 31.56 m/s.
Learn more about vertical velocity here: brainly.com/question/24949996
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Answer:
There is much more friction on the rough surface than there is on the smooth surface.
Explanation:
Answer:
Speed = 575 m/s
Mechanical energy is conserved in electrostatic, magnetic and gravitational forces.
Explanation:
Given :
Potential difference, U = 
Mass of the alpha particle, 
Charge of the alpha particle is, 
So the potential difference for the alpha particle when it is accelerated through the potential difference is

And the kinetic energy gained by the alpha particle is

From the law of conservation of energy, we get





The mechanical energy is conserved in the presence of the following conservative forces :
-- electrostatic forces
-- magnetic forces
-- gravitational forces