Answer:
<em>-2 units of charge</em>
Explanation:
charge on A = Qa = -6 units
charge on B = Qb = 2 units
if the spheres are brought in contact with each other, the resultant charge will be evenly distributed on the spheres when they are finally separated.
charge on each sphere will be = 
charge on each sphere = 
= 
= <em>-2 units of charge</em>
Explanation:
It is given that,
The speed of light in vacuum is, c = 299,792,458 m/s
The permeability constant of vacuum is, 
Let 
is the permittivity of free space. The relation between 
is given by :
Hence, this is the required solution.
Answer:
0.229 seconds
Explanation:
Given:
y₀ = 80.6 m
v₀ = 0 m/s
a = -9.8 m/s²
We need to find the difference in times when y = 10.8 m and y = 2.10 m.
When y = 10.8 m:
y = y₀ + v₀ t + ½ at²
10.8 = 80.6 + (0) t + ½ (-9.8) t²
10.8 = 80.6 − 4.9 t²
4.9 t² = 69.8
t = 3.774
When y = 2.10 m:
y = y₀ + v₀ t + ½ at²
2.10 = 80.6 + (0) t + ½ (-9.8) t²
2.10 = 80.6 − 4.9 t²
4.9 t² = 78.5
t = 4.003
The difference is:
4.003 − 3.774 = 0.229
The man has 0.229 seconds to get out of the way.
The heat needed is given by Mcθ , where m is the mass in Kg, c is the heat capacity of aluminium, and θ is the change in temperature.
Specific heat capacity of aluminium is 0.9 j/g°c
thus; Heat = 55 × 0.9 × 72.2
= 3573.9 Joules or 3.574 kJ
