Question is from B to C
Answer: (b) 1.5m/s
x1=3m, x2=9m
t1=1s, t2=5s
Displacement, ∆x=(9-3)m=6m
Time elapsed, ∆t=(5-1)s=4s
So average velocity v =∆x/∆t=6/4=1.5m/s
If you do not have to use relative physics but classic physics, this is how you solve it:
Speed of light = c = 3 * 10^5 km/s
Speed of your foe respect to you: 0.259c
Speed of the torpedo respect to you: 0.349c
Speed of the torpedo respect your foe: 0.349c - 0.259c = 0.09c
Conversion to km/s = 0.09 * 3.0 * 10^5 km/s = 27000 km/s
Note that this solution, using classic physics do not take into account time and space dilation.
Answer: 27000 km/s
when the two waves interfere with eachother to make a dark spot the periodic difference of the two waves is π . the wave length for 2π is 600nm
. ie. for π difference it is 300nm
Answer:
Temperature of the gas molecules is 7.96 x 10⁴ K
Explanation:
Given :
Ions accelerated through voltage, V = 10.3 volts
The work done to change the position of singly charged gas ions is given by the relation :
W = q x V
Here q is charge of the ions and its value is 1.6 x 10⁻¹⁹ C.
Average kinetic energy of gas molecules is given by the relation:
K.E. = 
Here T is temperature and k is Boltzmann constant and its value is 1.38 x 10⁻²³ J/K.
According to the problem, the average kinetic energy of gas is equal to the work done to move the singly charged ions, i.e. ,
K.E. = W

Rearrange the above equation in terms of T :

Substitute the suitable values in the above equation.

T = 7.96 x 10⁴ K