Work with your units:
1 watt-hour = 1 (joule/second) · (hour) = 1 (joule-hour / second)
(1 joule-hour/sec) · (3600 sec/hour) = 3600 joules
So 1 watt-hour = 3,600 joules
Answer:
45.88297 m
Violet
Explanation:
x = Gap between holes = 5.9 mm
= Wavelength = 527 nm
D = Diameter of eye = 5 mm
L= Distance of observer from holes
From Rayleigh criteria we have the relation

A person could be 45.88297 m from the tile and still resolve the holes
Resolving them better means increasing the distance between the observer and the holes. It can be seen here that the distance is inversely proportional to the wavelength. Violet has a lower wavelength than red so, violet light would resolve the holes better.
Answer:
a. when the acceleration of the objects become negative