Answer: 
Explanation:
Voltage is calculated by Ohm's Law:

Protons are positive, and neutrons are negative, electrons are neutral. I’m not sure about the rest but I hope that helps for now
Answer:
-0.7 m/s
Explanation:
Initial velocity (u)= 2.5 m/s
Acceleleration (a)= -0.8 m/s^2
Time taken (t) = 4 seconds
Hence,
v=u+at [1st Equation of motion]
v=2.5+-0.8*4
v=2.5-3.2
v=-0.7 m/s
Note that the negative sign indicates that the ball has changed direction and rolls downwards with gravity
Answer:
the mass of water is 0.3 Kg
Explanation:
since the container is well-insulated, the heat released by the copper is absorbed by the water , therefore:
Q water + Q copper = Q surroundings =0 (insulated)
Q water = - Q copper
since Q = m * c * ( T eq - Ti ) , where m = mass, c = specific heat, T eq = equilibrium temperature and Ti = initial temperature
and denoting w as water and co as copper :
m w * c w * (T eq - Tiw) = - m co * c co * (T eq - Ti co) = m co * c co * (T co - Ti eq)
m w = m co * c co * (T co - Ti eq) / [ c w * (T eq - Tiw) ]
We take the specific heat of water as c= 1 cal/g °C = 4.186 J/g °C . Also the specific heat of copper can be found in tables → at 25°C c co = 0.385 J/g°C
if we assume that both specific heats do not change during the process (or the change is insignificant)
m w = m co * c co * (T eq - Ti co) / [ c w * (T eq - Tiw) ]
m w= 1.80 kg * 0.385 J/g°C ( 150°C - 70°C) /( 4.186 J/g°C ( 70°C- 27°C))
m w= 0.3 kg