Q. 685.0( 3 Votes )

Two identical particles, each having a charge of 2.0 × 10–4 C and mass of 10g, are kept at a separation of 10 cm and then released. What would be the speeds of the particles when the separation becomes large?

Answer :

Charge on two identical particles: q1=q2= 2.0 × 10–4 C
Mass of the two particles : m1=m2= m = 10 g = 0.01 kg
Separation between the charges : r = 10 cm = 0.1 m
Formula used:
When they are released, the force of repulsion will be acting on both the particles making them drift apart thereby increasing distance between them.
Potential Energy at the start will be
where Uinitial is the initial potential energy between the charges ,k is a constant and k= =9× 109 Nm2C-2 , q1 and q2 are point charges and r is the separation between them.
Final Potential energy would be zero as the particles will gain Kinetic energy and the separation between the charges would approach infinity : Ufinal = 0
Now by conservation of energy:
Total kinetic energy is :
Where , m is the mass of the particles and V is the velocity gained by the particles.

Hence, when the separation becomes large the speed of the particles should be 600 m/s.

Rate this question :

How useful is this solution?
We strive to provide quality solutions. Please rate us to serve you better.
Related Videos
Superfast Revision of Potential & Potenial Energy (Theory + Interactive Quiz)47 mins
Check your knowledge of Electric Potential | Quiz45 mins
Relation between electric field and potential34 mins
Relation between Electric field & Potential45 mins
Interactive quiz on Relation between electric field and potential43 mins
Electric field inside cavity37 mins
Few Applications of Gauss's law54 mins
Test Your Knowledge of Electric Charge & Coulomb's Law47 mins
Electric potential inside solid and hollow sphere30 mins
Electric Field Lecture47 mins
Try our Mini CourseMaster Important Topics in 7 DaysLearn from IITians, NITians, Doctors & Academic Experts
Dedicated counsellor for each student
24X7 Doubt Resolution
Daily Report Card
Detailed Performance Evaluation
view all courses