Answer:E
Explanation:
It is given that Energy of gamma ray is E=1.2 Mev
Shielding effect can be measured by measuring the fraction of gamma rays blocked by shield. If certain thickness will able to block half the radiation then to block 75% radiation we need to add same amount of thickness in order to block the remaining radiation.
i.e. 
fraction is blocked by 10 cm thickness
then remaining radiation is
another 10 cm thickness will block the remaining half radiation i.e. 
so total 75 % radiation will be blocked
Answer: 1477.78 N
Explanation:
Let's assume that the cross sectional area of the smaller piston be A1
let's also assume the cross sectional area of the larger piston be A2
We assume the force applied to the smaller piston be F1
We also assume the force applied to the larger piston be F2
we then use the formula
F1/A1 = F2/A2
From our question,
The radius of the smaller piston is 5 cm = 0.05 m
The radius of the larger piston is 15 cm = 0.15 m
The force of the larger piston is 13300 N
The force of the smaller piston is unknown = F
A1 = πr² = 3.142 * 0.05² = 0.007855 m²
A2 = πr² = 3.142 * 0.15² = 0.070695 m²
F1/0.007855 = 13300/0.070695
F1 = (13300 * 0.007855) / 0.070695
F1 = 104.4715 / 0.070695
F1 = 1477.78 N
Thus, the force the compressed air must exert is 1477.78 N
Q before connected = Q after connected C1V1+C2V2 = (C1+C2) V
C1= 3×10^-6 F
V1= 480v
C2= 4×10^-6 F
V2= 500v
(3×10^-6)×(480) + (4×10^-6)×(500) = (3×10^-6 + 4×10^-6) × V
Simplifying the above, we get:
( 1440× 10^-6) + (2000 ×10^-6) = (7 × 10^-6) × V.
Further simplified as:
3440 × 10^-6 = 7 × 10^-6 × V
Making V the subject
V = 491.43volts
Therefore the potential difference across each capacitor is 491.43v
Answer:
0.64 J/g°C
Explanation:
Using the formula;
Q = m × c × ∆T
Where;
Q = amount of heat
m = mass (g)
c = specific heat capacity
∆T = change in temperature (°C)
In this case:
Q (water) = - Q (metal)
mc∆T (water) = - mc∆T (metal)
According to the information in this question,
For water; m = 100g, c = 4.18J/g°C, ∆T = (25°C - 20°C)
For metal; m = 50g, c =?, ∆T = (25°C - 90°C)
mc∆T (water) = - mc∆T (metal)
100 × 4.18 × (25°C - 20°C) = - {50 × c × (25°C - 90°C)}
100 × 4.18 × 5 = - {50 × c × -65}
2090 = -{-3250c}
2090 = 3250c
c = 2090/3250
c = 0.643
c = 0.64J/g°C
