Answer:

Explanation:
Given that,
The distance between two spheres, r = 25 cm = 0.25 m
The capacitance, C = 26 pF = 26×10⁻¹² F
Charge, Q = 12 nC = 12 × 10⁻⁹ C
We need to find the work done in moving the charge. We know that, work done is given by :

Put all the values,

So, the work done is
.
Answer : The correct option is, (C) 17 m/s
Explanation :
Formula used :

where,
K.E = kinetic energy = 6.8 J
m = mass of object = 46 g = 0.046 kg (1 kg = 1000 g)
v = velocity
Now put all the given values in the above formula, we get:




Therefore, the ball's velocity be as it leaves the cannon is, 17 m/s
Answer:
3.98V
Explanation:
Given
Pontential difference V as 3v
Energy delivered is 30%,
Recall that Enery E=1/2cv^2 from this E=V^2(since Current C is not provided we can assume a value 2)
So E=V^2
E=3^2=9
At full charge E=9,30%of 9,0.3*9=2.7 energy in capacitor is 9-2.7=6.3
But E=V^2
✓E=V
✓6.3=3.98V
Answer:
Force is 57.69 N to the opposite direction of motion of dolphin.
Explanation:
We have force is the product of mass and acceleration.
That is
Force = Mass x Acceleration
F = ma
Mass of dolphin, m = 30 kg
We have equation of motion, v = u + at
Final velocity, v = 7 m/s
Initial velocity, u = 12 m/s
Time, t = 2.60 s
Substituting
7 = 12 + a x 2.6
a = -1.92 m/s²
Force, F = 30 x -1.92 = -57.69 N
So the force is 57.69 N to the opposite direction of motion of dolphin.