ANSWER

EXPLANATION
First, let us make a sketch of the question:
From the diagram:
=> black line represents North
=> green line represents East
=> blue line represents West
=> red line represents South
From the diagram, we see that at the end of his journey, he returns to his start point.
Since displacement is the measure of the change in the position of an object and the boy's position did not change after the journey, his displacement is:
Answer:
B. 805 m east
Explanation:
Δx = (23 m/s east) (35 s)
Δx = 805 m east
Answer:
Explanation:
charge, q = 2e = 2 x 1.6 x 10^-19 C = 3.2 x 10^-19 C
mass, m = 4 u = 4 x 1.661 x 10^-27 kg = 6.644 x 10^-27 kg
Radius, r = 4.5 cm = 0.045 m
Magnetic field, B = 1.20 T
(a) Let the speed is v.


v = 2.6 x 10^6 m/s
(b) Let T be the period of revolution


T = 1.09 x 10^-7 s
(c) The formula for the kinetic energy is


K = 2.25 x 10^-14 J
(d) Let the potential difference is V.
K = qV


V = 70312.5 V
Answer:
a. chemical contamination of streams ans rivers
d. adaptation
Answer:
C) upward
Explanation:
The problem can be solved by using the right-hand rule.
First of all, we notice at the location of the negatively charged particle (above the wire), the magnetic field produced by the wire points out of the page (because the current is to the right, so by using the right hand, putting the thumb to the right (as the current) and wrapping the other fingers around it, we see that the direction of the field above the wire is out of the page).
Now we can apply the right hand rule to the charged particle:
- index finger: velocity of the particle, to the right
- middle finger: direction of the magnetic field, out of the page
- thumb: direction of the force, downward --> however, the charge is negative, so we must reverse the direction --> upward
Therefore, the direction of the magnetic force is upward.