Physics Answers

•Q2. the position of a particle moving along the x-axis is given by

                                x= 7.8 + 9.2t -2.1 t3  

Where x is in meters and t is in seconds.

a). What is the velocity at t=3.5s?

b). Is the velocity constant or continuous?

c). What is the displacement of the particle after 3.5 seconds?

d). Sketch   i. displacement - time graph

                    ii. Velocity – time graph

                    iii. Acceleration-time graph

For the particle motion within the time o ≤ t ≤ 6s

 If two charges are fixed such that the distance r between them does not change, but the charge q₁ is decreased by half, what is the new force?

two charges are not changed but they are moved twice farther than the original distance r, what becomes of the new electric force?

Two charges q and Q are separated by a distance R. If both charges are doubled to 2q and 2Q but the distance R remains the same, the new electric force is _____ the old force.

1.   Three point charged particles are arranged in a line as shown in the figure below. Charge A = -5 µC, charge B = +10 µC, and charge C = -12 µC. Calculate the net electrostatic force on particle B due to the other two charges.

How far apart are two charges , one of magnitude is 3 uC and the other magnitude is 5uC if the force between them is 20N

If two electrons are 1.50 x 10^-10 m each from a proton, find the magnitude and direction of the net electric force they will exert on the proton.

Two small spheres spaced apart have equal charge. How many electrons must be present on each sphere if the magnitude of the force of repulsion between them is 4.57 x 10^-21 N?

Two equal positive charges q1 = q2 = 4.0 μC are located at x = 0, y = 0.30 m, x = 0, y = -0.30 m and respectively. What are the magnitude and direction of the total electric force that q1 and q2 exert on a third charge at Q = 4.0 μC x = 0.40 m, y = 0?

Two point charges are located on the -axis of a coordinate system: q1 = 1.0 nC is at x = +2.0 cm, and q2 is at x = +4.0 cm. What is the total electric force exerted by q1 and q2 on a charge q3 = 5.0 nC at x = 0?

Lightning occurs when there is a flow of electric charge (principally electrons) between the

ground and a thundercloud. The maximum rate of charge flow in a lightning bolt is about 20,000 C/s this lasts for 100 μs or less. How much charge flows between the ground and the cloud in this time? How many electrons flow during this time?