B is the answer
Explanation: look at the graph
Answer:
0.000109375 m
Explanation:
d = Distance between grating = 0.5 mm
m = Order

Minima relation

For fourth order minima

For second maxima

From the two equations we get

The wavelength is 0.000109375 m
Explanation:
Things move in a different direction
The acceleration due to gravity is 1.62m/s^2, this is because the moons gravity is 1/6th that of Earth's (9.81m/s^2) hope this helps! you could also use Newton's law of gravity, F=GM/R^2 where g is the universal gravitational constant, M= mass of the object and R=radius. There should be a neg sign in front of the equation since objects in free fall fall downwards from the given object. Hope this Helps........