The focal point of a concave mirror is halfway along the radius, therefore the radius would be 2•16= 32 cm
Answer:
Explanation:
density of galaxies would be 
times higher which is equal to 50.81.
It means in a cube that today contains one galaxy the size of the Milky Way, we would instead find 50.81 galaxies this size.
You can round this off to 52
(a) Zero
The maximum efficiency (Carnot efficiency) of a heat engine is given by
where
is the low-temperature reservoir
is the high-temperature reservoir
For the heat engine in the problem, we have:
Therefore, the maximum efficiency is
(b) Zero
The efficiency of a heat engine can also be rewritten as
where
W is the work performed by the engine
is the heat absorbed from the high-temperature reservoir
In this problem, we know
Therefore, since the term cannot be equal to infinity, the numerator of the fraction must be zero as well, which means
W = 0
So the engine cannot perform any work.
Answer:
a) k = 2231.40 N/m
b) v = 0.491 m/s
Explanation:
Let k be the spring force constant , x be the compression displacement of the spring and v be the speed of the box.
when the box encounters the spring, all the energy of the box is kinetic energy:
the energy relationship between the box and the spring is given by:
1/2(m)×(v^2) = 1/2(k)×(x^2)
(m)×(v^2) = (k)×(x^2)
a) (m)×(v^2) = (k)×(x^2)
k = [(m)×(v^2)]/(x^2)
k = [(3)×((1.8)^2)]/((6.6×10^-2)^2)
k = 2231.40 N/m
Therefore, the force spring constant is 2231.40 N/m
b) (m)×(v^2) = (k)×(x^2)
v^2 = [(k)(x^2)]/m
v = \sqrt{ [(k)(x^2)]/m}
v = \sqrt{ [(2231.40)((1.8×10^-2)^2)]/(3)}
= 0.491 m/s
