A beta particle. Hoped I help. Sorry if it wrong.
Answer:

Explanation:

1+7 = 6+2 =8 -protons
1+15 = 12+4 = 16 - protons +neutrons
Answer:
The time is 106.7 minute.
Explanation:
Given that,
Density 
Current 
Diameter of wire = 1.2 mm
Length = 31 cm
We need to calculate the drift velocity
Using formula of drift velocity


Put the value into the formula


We need to calculate the time
Using formula for time


Where, l = length
= drift velocity
Put the value into the formula



Hence, The time is 106.7 minute.
Answer:
50 N
Explanation:
Efficiency of a machine can't be more than 1, so I assume you mean 40%. (Remember, efficiency and mechanical advantage are not the same).
Efficiency is the ratio of work out of a system to the work in to the system.
e = Wout / Win
Work is force times distance, so:
e = (Fout × Dout) / (Fin × Din)
Rearranging:
Fin = (Fout × Dout) / (e × Din)
Fin = (Fout / e) × (Dout / Din)
Fin = (Fout / e) / (Din / Dout)
We know that e = 0.40, and Fout = 120 N. Since there are 6 pulleys, we also know that Din/Dout = 6.
F = (120 N / 0.4) / 6
F = 50 N