Answer:
Explained
Explanation:
i)Two spheres hanging from nylon threads attract each other because either the two spheres are charged with opposite sign or only one of the spheres is charge so the other would be charge by induction of the charged sphere and hence attract each other.
ii)However, when they are touched the charges will be rearranged among the two sphere such that the two sphere have exact same magnitude and sign of charge and now they will repel each other or the magnitude of charges on the two spheres become zero and they neither attract or repel each other.
Answer:
Txomin lifted the stone with greater mass. (Txomin levantó la roca con mayor fuerza).
Explanation:
The sportsman that lifts the stone with a greater mass needs a higher force (El deportista que levanta la piedra con mayor masa necesita una mayor fuerza):
José


Txomin


Txomin lifted the stone with greater mass. (Txomin levantó la roca con mayor fuerza).
(a) 
The radiation pressure exerted by an electromagnetic wave on a surface that totally absorbs the radiation is given by

where
I is the intensity of the wave
c is the speed of light
In this problem,

and substituting
, we find the radiation pressure

(b) 
Since we know the cross-sectional area of the laser beam:

starting from the radiation pressure found at point (a), we can calculate the force exerted on a tritium atom:

And then, since we know the mass of the atom

we can find the acceleration, by using Newton's second law:

The formula for kinetic energy is

. Thus, the equation for velocity is

.