Answer: B. I hope you get this right.
Answer:
0.002833 sec
Explanation:
Speed of light in vacuum is 
Given distance = 850 km = 850×1000=850000 m
We have to calculate the time that light take to travel the distance 850 km
Time 
So the time taken by light to travel 850 km is 0.002833 sec
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
There's a short handy formula for that.
If the object is just dropped and not tossed, and it's not affected by air resistance on the way down, then the distance it falls in T seconds is
D = (1/2) (gravity) (T²)
For this problem . . .
176.4 m = (1/2) (9.8 m/s²) (T²)
Divide each side by (4.9 m/s²) :
T² = (176.4 m) / (4.9 m/s²)
T² = (36 s²)
Take the square root of each side:
<em>T = 6 seconds</em>
The first person = A
The second one = B
velocity of A = 3 km / h
velocity of B = 4 km / h
Distance of A = 3t
Distance of B = 35 - 4t
At what time do they meet?
3t = 35 - 4t
7t = 35
t = 5 hours
7 a.m. + 5 hours = 12 p.m.
