Answer:
Answered
Explanation:
The data given in the problem
Diameter of a human pupil=0.007 m=7 mm
Diameter of alien pupil=0.5=500 mm
Here we have to calculate the minimum distance at which the alien can see Betelgeuse i.e. the focal length (or the working distance). For this calculation we assume the eye to be a spherical lens.
The focal length and diameter of the lens are related by the formula 
Where r is radius of curvature i.e. d/2
Therefore for the alien, focal length=
=12.5mm=0.0125
Question :-
- If a Train going with 60 m/s Speed hits the Brakes, and takes 85 sec to stop. What is the Acceleration of the Train ?
Answer :-
- Acceleration of Train is 0.70 m/s² .
Explanation :-
As per the provided information in the given question, we have been given that the Speed of the Train is 60 m/s . Time taken to stop the Train is 85 sec . And, we have been asked to calculate the Acceleration of the Train .
For calculating the Acceleration , we will use the Formula :-
Where ,
- V denotes to Final Velocity .
- U denotes to Initial Velocity .
- T denotes to Time Taken .
Therefore , by Substituting the given values in the above Formula :-
Hence :-
- Acceleration = 0.70 m/s² .
Note :-
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Tension in the rod is responsible for balancing force due to gravity.
The gravitational potential energy as a rollercoaster converts to kinetic energy when it moves downhill.
<h3>
What is kinetic energy?</h3>
The kinetic energy of an object or body is due to its motion. When the roller coaster moves downhill it accelerates, thus the gravitational potential energy as a rollercoaster converts to kinetic energy.
The gravitational potential energy of an object or body is due to its position above the ground.
Therefore, the gravitational potential energy as a rollercoaster converts to kinetic energy when it moves downhill.
Learn more about kinetic energy:
brainly.com/question/1250558
Answer:
ρ_body = 1000 kg / m³
Explanation:
This is an exercise in fluid mechanics, specifically we must use the Archimedean principle, which states that the thrust is equal to the weight of the dislodged liquid.
In this case let's start by finding the volume of our body
oak block
v = l to h
v = 0.02 0.02 0.05
V = 2 10⁻⁵ m³
cooper block indicate that it has the same dimensions so its volume is the same, the total volume of the body is
V_total = 4 10⁻⁵ m³
as they indicate that the body is fully submerged there is a balance between weight and thrust
B - W = 0
the push is
B = ρ_fluid g V_total
the body weight is
ρ_body = M / V_total
M = ρ_body V_total
W = Mg
W = ρ_body V_total g
we substitute
ρ_fluid g V_total = ρ_body V_total g
ρ_body = ρ_fluid
in this case the body is in equilibrium in the fluid, in case the density of the body is greater than that of the fluid, the body sinks
Therefore the average density is equal to the density of the fluid, since since it is water the density is
ρ_body = 1000 kg / m³
