An airplane starts from rest and reaches a takeoff velocity of 60.0m/s due north in 4.0 s. How far has it traveled before takeof
1 answer:
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Answer: The correct option is Option b.
Explanation:
Power is defined as the rate of work done by an object.
Mathematically,
.....(1)
And work done is the product of force exerted on the object times the displacement covered by that object.
Mathematically,
Putting this value in above equation, we get:
where,
P = power = ?W
F = Force exerted = 10N
s = Displacement = 400cm = 4m (Conversion factor: 1m = 100 cm)
t = Time taken = 8s
Putting values in above equation, we get
Hence, the correct option is Option b.
Here refrigerator removes 55 kcal heat from freezer
Refrigerator releases 73.5 kcal heat to surrounding
So here we can use energy conservation principle by II Law of thermodynamics
the law says that
here we know that
= heat released to the surrounding
= heat absorbed from freezer
W = work done by the compressor
now using above equation we can write
So here compressor has to do 18.5 k cal work on it
The options of the question are missing. I have attached it.
Answer:
Satellite in option B will have the greatest speed.
Explanation:
From kepplers third law, we know that
V² = GM/R
Thus, v = √(GM/R)
Where;
v is velocity
G is gravitational constant
M is mass
R is radius
Looking at the options, let's start from the first one;
Option A
Here, mass = (1/2)m and radius = R
So, v = √(GM/R) thus v = √(G(m/2)/R) = √(Gm/2R)
Option B
Here, mass = m and radius = (1/2)R
Thus v = √(Gm/(R/2)) = √(2Gm/R)
Option C
Here, mass = m and radius = R
Thus v = √(Gm/R)
Option D
Here, mass = m and radius = 2R
Thus v = √(Gm/(2R))
Now, inspecting all the options, it's clear that option B will have the greatest velocity because it's numerator is the biggest and will in turn lead to higher velocity.
