Explanation:
Speed of Bob, v = 0.967 c
At the exact instant he passes Alice, she fires a very short laser pulse in the same direction Bob is moving.
(a) We need to find the distance measured by Alice between Bob and the laser pulse. It is given by :




(b) Distance measured by Bob between himself and the laser pulse is given by :



Hence, this is the required solution.
Explanation:
It is given that,
Length of wire, l = 0.53 m
Current, I = 0.2 A
(1.) Approximate formula:
We need to find the magnitude of the magnetic field made by the current at a location 2.0 cm from the wire, r = 2 cm = 0.02 m
The formula for magnetic field at some distance from the wire is given by :


B = 0.000002 T

(2) Exact formula:


B = 0.00000199 T
or
B = 0.000002 T
Hence, this is the required solution.
Answer:
a) Current = 11 mA
b) Energy = 66 mJ
c) Power = 101.54 W
Explanation:
a) Voltage, V = IR
Voltage, V = 6 V, Resistance, R = 550 Ω
Current, I 
b) Energy = Current x Voltage = 6 x 0.011 = 0.066 J = 66 mJ
c)
Answer:2.103 m/s
Explanation:
Given
mass of sports car 
mass of SUV 
Suppose u is the velocity if sports car before collision
Conserving momentum we get



After collision the combined mass drag 2.8 m and finally stops
From work energy theorem work done by friction is equal to change in kinetic energy of the combined mass system

where 




Initial velocity 
