Answer:When the Moon is in the position shown below, how would the Moon look to an observer on the North Pole? The moon's rotational period is equal to its revolutional period around Earth. This statement is false because at night we see one side and during the day we see the opposite.
Explanation:
Solve for the linear/tangential speed:
<em>a</em> = <em>v</em>²/<em>r</em>
where <em>a</em> = centripetal acceleration, <em>v</em> = speed, and <em>r</em> = radius.
4.7 m/s² = <em>v</em>²/(0.3 m)
<em>v</em>² = (0.3 m) (4.7 m/s²)
<em>v</em> ≈ 3.96 m/s
For every time the record completes one revolution, a fixed point on the edge of the record travels a distance equal to its circumference, which is 2<em>π</em> (0.3 m) ≈ 1.88 m. So if 1 rev ≈ 1.88 m, then the angular speed of the record is
(3.96 m/s) (1/1.88 rev/m) ≈ 7.46 rev/s
Take the reciprocal of this to get the period:
1 / (7.46 rev/s) ≈ 0.134 s/rev
So it takes the record about 0.134 seconds to complete one revolution.
Answer:
the thickness of the mica is 6.64μm
Explanation:
By definition we know that the phase between two light waves that are traveling on different materials (in this case also two) is given by the equation
Where
L = Thickness
n = Index of refraction of each material
Our values are given as
Replacing our values at the previous equation we have
the thickness of the mica is 6.64μm
Explanation:
It is given that,
Work done, W = 240 J
Heat removed, Q = 610 J
(a) The refrigerator's coefficient of performance is given by :
COF = 2.54
(b) Let Q' is the heat per cycle is exhausted to the kitchen. It is given by :
Q' = Q + W
Q' = 610 + 240
Q' = 850 J
Hence, this is the required solution.
Answer:
This depends on what angle they are approaching each other before they collided.The two simple cases are if they are running in the same direction or opposite direction from each other. For either case, use the conservation of momentum equation to solve: M_total*V_result = M1*V1 + M2*V2
Explanation:
Here are two possible solutions.
Head-on collision: M1=78, V1=8.5, M2=72, V2=-7.5 (that's negative because he's running the other way), M_total = 78+72 = 150, so V_result = (78*8.5 - 72*7.5)/150 = 0.82 m/s. Sanity check, they weigh about the same and so most of their velocity should cancel out.
Running the same way: change the sign of V2 to positive so V_result = (78*8.5 + 72*7.5)/150 = 8.02 m/s. Sanity check, they weigh about the same and the resultant speed is between the two starting velocities.
<em>hope it helps:)</em>
