I believe the answer is C. an increase in the number of cold climates
the answer your looking for is Optical instrument.
Answer:
36 N
Explanation:
If the object of mass, m = 8 kg is swung in a horizontal circle of radius, r = 2m = length of string with tangential velocity v = 3 m/s, the tension in the string is the centripetal force which is T = mv²/r
= 8 kg × (3 m/s)²/2 m
= 4 kg × 9 m/s²
= 36 N