Answer:
if the river is 5km wide and is flowing at 4km/hr. eastwards find by scale ... Find either by scale drawing or by calculation (1) the direction in which he must ... He could row his boat directly across the river to point C and then run to B, or he ... A man who can swim at 5km/h in still water swims towards the east to cross arriver.
Explanation:
Answer:
Magnification, m = 3
Explanation:
It is given that,
Focal length of the lens, f = 15 cm
Object distance, u = -10 cm
Lens formula :

v is image distance

Magnification,

So, the magnification of the lens is 3.
Answer:
<em>radius of the loop = 7.9 mm</em>
<em>number of turns N ≅ 399 turns</em>
Explanation:
length of wire L= 2 m
field strength B = 3 mT = 0.003 T
current I = 12 A
recall that field strength B = μnI
where n is the turn per unit length
vacuum permeability μ =
= 1.256 x 10^-6 T-m/A
imputing values, we have
0.003 = 1.256 x 10^−6 x n x 12
0.003 = 1.507 x 10^-5 x n
n = 199.07 turns per unit length
for a length of 2 m,
number of loop N = 2 x 199.07 = 398.14 ≅ <em>399 turns</em>
since there are approximately 399 turns formed by the 2 m length of wire, it means that each loop is formed by 2/399 = 0.005 m of the wire.
this length is also equal to the circumference of each loop
the circumference of each loop = 
0.005 = 2 x 3.142 x r
r = 0.005/6.284 =
= 0.0079 m =<em> 7.9 mm</em>
Answer:
V = 2.5 J/C
Explanation:
<u><em>Given:</em></u>
Energy = E = 20 J
Charge = Q = 8 C
<u><em>Required:</em></u>
Potential Difference = V = ?
<u><em>Formula:</em></u>
V = 
<u><em>Solution:</em></u>
V = 20/8
V = 2.5 J/C
To find the number of electrons transferred, we should divide the total charge acquired by the rod

by the charge of a single electron (

), and we find: