A beta particle followed by another beta particle. Consider it beta positive decay in which a proton decays to form a neutron,positron and electron neutrino.
Answer:
f = 4 Hz
Explanation:
Given that,
The speed of a wave, v = 12 m/s
The wavelength of a wave, 
We need to find the frequency of the wave. We know that the speed of wave is equal to the product of wavelength and frequency. So,

So, the frequency of the wave is equal to 4 Hz.
Answer:
1.23 m/s
Explanation:
The kinetic energy of the sprinter is:
KE = 0.5 * m(s) * v²
KE = 0.5 * 77 * 7.5²
KE = 2165.63 J
If the KE of the sprinter and the KE of the elephant are equal, hence:
2165.63 = 0.5 * m(e) * v²
2165.63 = 0.5 * 2850 * v²
=> v² = 1.52
v = √(1.52)
v = 1.23 m/s
Answer:
The answer is: measuring instrument
Explanation:
The researcher develops test to measure the variables she is interested in. So, they are her measuring instrument.
I’m not sure but I think it’s D because we don’t have 20,000 years to make observations