PE = mgh
Mass, m = 7kg, g ≈ 10 m/s², height = 2m
= 7*10*2
= 140 Joules.
True no object can travel faster than speed of light
Answer:
3100 m/s
Explanation:
The relationship between frequency and wavelength of a wave is given by the wave equation:

where
v is the speed of the wave
f is its frequency
is the wavelength
For the wave in this problem,
f = 15,500 Hz

Therefore, the wave speed is

D, electron, the nucleus is not a single particle to begin with, the proton has a positive charge, a neutron has a neutral charge or no charge, and an electron has a negative charge