Calculati rezistenta filamentului unui bec al lanternei de buzunar daca la tensiunea de 3,5 v el este parcurs de un curent cu in
1 answer:
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Answer:
Part 1) Time of travel equals 61 seconds
Part 2) Maximum speed equals 39.66 m/s.
Explanation:
The final speed of the train when it completes half of it's journey is given by third equation of kinematics as
where
'v' is the final speed
'u' is initial speed
'a' is acceleration of the body
's' is the distance covered
Applying the given values we get
Now the time taken to attain the above velocity can be calculated by the first equation of kinematics as
Since the deceleration is same as acceleration hence the time to stop in the same distance shall be equal to the time taken to accelerate the first half of distance
Thus total time of journey equals
Part b)
the maximum speed is reached at the point when the train ends it's acceleration thus the maximum speed reached by the train equals
Answer:
The same as the escape velocity of asteorid A (50m/s)
Explanation:
The escape velocity is described as follows:
where is the universal gravitational constant,
is the mass of the asteroid and
is the radius
and since the scape velocity is 50m/s:
Now, if the astroid B has twice mass and twice the radius, we have that tha mass is:
and the radius is:
inserting these values into the formula for escape velocity:
and we have found that , so the two asteroids have the same escape velocity.
We found that the expression for escape velocity remains the same as for asteroid A, this because both quantities (radius and mass) doubled, so it does not affect the equation.
The answer is
Asteroid B would have an escape velocity the same as the escape velocity of asteroid A
Answer:
1.23 m
Explanation:
The vertical distance covered by a free-falling object starting from rest in a time t is
where
g = 9.8 m/s^2 is the acceleration due to gravity
In this problem, we have
t = 0.50 s
So the distance covered is