<em>Answer: D</em>
<em>Given data:</em>
The electric field due to charge q₁ is (E₁) = 1.5 × 10⁵ N/C
The electric field due to charge q₂ is (E₂) = 7.2 × 10⁵ N/C
Determine the net electric field at point P (Enet) = ?
electric field measured in Newtons/coulomb
<em>We know that,</em>
The net electric field (Enet) is vector sum of E₁ and E₂ caused by the charge q₁ and q₂ respectively
Enet = E₁ + E₂
= (1.5 × 10⁵)+ (7.2 × 10⁵)
= 8.7 × 10⁵ Newtons/coulomb
<em>The net electric field at point P is 8.7 × 10⁵ N/C</em>
Answer;
C.It is the minimum amount of material needed to sustain a fission reaction.
Explanation;
-A critical mass is the smallest or the minimum amount of fissile material needed for a sustained nuclear chain reaction. A critical mass must be achieved in order for the chain reaction to continue and release the atomic energy. A critical mass is needed for both a nuclear reactor and an atomic or hydrogen bomb.
-The critical mass of a fissionable material depends upon its nuclear properties (specifically, the nuclear fission cross section), its density, its shape, its enrichment, its purity, its temperature, and its surroundings.
Answer:
3.97 m/s
Explanation:
Speed is defined as the distance covered per unit time. Therefore, s=d÷t=d/t
Where d is distance and t is time
Given distance of 5 km and time of 21 minutes the speed would be given by dividing 5 km by 21 min. However, speed is expressed as km/h or m/s or miles per hour etc. So we nees to get our speed in one of these standard units.
Going for m/s
Conversion
1 km has 1000m hence
5 km=5*1000=5000m
1 min has 60 seconds hence
21 min=21*60=1260 s
Speed=5000m÷1260s=3.9682539682538 m/s
Rounded off, s=3.97 m/s
Answer:
Explanation:
Given mass of piston 
no. of moles =n
Given Pressure remains same
Temperature changes from 
Work done
W=
also 

