Answer:

Explanation:
Since we know that two sphere is oppositely charged so net electric field at the mid point of two balls will be sum of the electric field due to each ball at the mid point
So we know that

here we know that



so we have


Answer:
Explanation:
The velocity of a wave in a string is equal to:
v = √(T / (m/L))
where T is the tension and m/L is the mass per length.
To find the mass per length, we need to find the cross-sectional area of the thread.
A = πr² = π/4 d²
A = π (3.0×10⁻⁶ m)²
A = 2.83×10⁻¹¹ m²
So the mass per length is:
m/L = ρA
m/L = (1300 kg/m³) (2.83×10⁻¹¹ m²)
m/L = 3.68×10⁻⁸ kg/m
So the wave velocity is:
v = √(T / (m/L))
v = √(7.0×10⁻³ N / (3.68×10⁻⁸ kg/m))
v ≈ 440 m/s
The speed of sound in air at sea level is around 340 m/s. So the spider will feel the vibration in the thread before it hears the sound.
Lets suppose center of cube as origin.
All charges are equidistant from this point .
Distance = 0.5*s*√<span>(3). </span>
Total work done = 8*(9*10^9)*q/(0.5*s*√<span>(3) =
Total work </span><span> required to assemble eight identical point charges= </span>(8.31*10^10)*q J
<span>The student's power rating is approximately 800W.
</span>
Power is the rate of doing work. Its SI unit is Watt. 1 W = 1J/sec
Given: <span>The work done to get to the top is 1200 Joules
</span>
Time = 1.5 seconds.
Power =
Answer:
b. Research projects for a specific cause
Explanation:
Research funded by private foundations are usually for a specific cause. These type of research are usually properly scrutinized, and must have a high probability of success. Most of these projects may not be to benefit the consumers, but are usually done with a special purpose in mind.