Answer:
4 hertz
Explanation:
The defination of freqyency = the total no of cycle made by a wave in one second .
so,
cycle or vibrations=60
tame taken = 15
now,
frequency = no. of cycle / time taken
= 60/15
=4 hertz
hence, the its frequency = 4hertz
Answer: The theory might have become Obsolete or Superseded
Explanation:
A theory becomes obsolete or superseded if it becomes inadequate, false or incomplete in how its describes reality. It does not matter if it was once accepted. There are some theories such as Lysenkoism that are currently described as being obsolete because it does not conform to current reality. Another example of a theory that was superseded is the phlogiston theory. It was replaced a different theory of energy.
D. Mineral and fossil matches from tests done on different continents.
Answer:
Explanation:
From the given information:
the car's momentum = momentum of the truck
∴
(a) 816 kg × v = 2650 kg × 16.0 km/h
v = (2650 kg × 16.0 km/h) / 816 kg
v = 51.96 km/hr
(b) 816 kg × v = 9080 kg × 16.0 km/h
v = (9080 kg × 16.0 km/h) / 816 kg
v = 178.04 km/hr