Answer:
Explanation:
It is given that,
Mass of the golf ball, m = 46 g = 0.046 kg
Terminal speed of the ball, v = 44 m/s
The drag force, 
Where, C is the drag coefficient. At terminal speed, the weight of the ball is balanced by the drag force.
Hence, this is the required solution.
Most geologists accept radiometric dating techniques as valid because radioactive elements decay at a constant and measurable rate.
Answer: Option C
<u>Explanation:</u>
Scientists prefer radioactive dating to carbon dating because it is more accurate in measuring. The analysis depends upon the radioactive decay of radioactive isotopes of any matter in a given rock or soil.
The parent atoms and daughter atoms are compared while studying, and hence age can be calculated easily. Radioactive decay depends upon the given half-life of the atom, which is a constant and is known. So, it would be very easy to calculate the number of progeny atoms and parent atoms and find out their age.
Answer:
The frequency of the phonograph record is 0.2 Hz
Explanation:
The frequency of an object moving in uniform circular motion is the number of completed cycles the object makes in a specified time period
The given parameters of the phonograph record are;
The radius of the record = 0.15 m
The number of times the phonograph record rotates, n = 18 times
The time it takes the phonograph record to rotate the 18 times, t = 90 seconds
The frequency of the phonograph record, f = (The number of times the phonograph record rotates) ÷ (The time it takes the phonograph record to rotate the 18 times)
∴ The frequency of the phonograph record, f = n/t = 18/(90 s) = 0.2 Hz
The frequency of the phonograph record = 0.2 Hz.
