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 Homework Statement:

1. Two aircraft depart simultaneously from the same location along perpendicular trajectories, with constant speeds equal to 300 km/h and 250 km/h, respectively. The two aircraft can communicate directly with each other only if they are less than 10 km apart. How long after departure will the two aircraft be out of communications range?
2. The New Horizons spacecraft was launched by NASA to study the dwarf planet Pluto in January of 2006. In July, 2015, the spaceship arrived at Pluto’s vicinity and sent back pictures of its surface. The estimated distance between Earth and the craft, at its closest approach point to Pluto, was 32 au (astronomical unit; 1 au = 1.50 × 108 km). Considering that the speed of light is 3.0 × 105 km/s, the image received by Earth observatories traveled, from New Horizons to Earth, during approximately:
A. 0.1μs
B. 1h
C. 4.5h
D. 2d
E. 0s
 Relevant Equations:

⃗v = ∆⃗x ∆t
⃗x = ⃗x 0 + ⃗v t
⃗a = ∆⃗v ∆t
⃗v = ⃗v 0 + ⃗a t
v 2 = v 20 + 2 a ( x − x 0 )
⃗x = ⃗x + v⃗ t + 1 ⃗a t 2
I am new to physics and these are my last two questions of my homework. I am extremely confused on what to do but I do know that for question 1 I need to create a triangle and solve for the hypotenuse, and for question 2 I believe I need to input my given values into the equation for position/displacement: ⃗x = ⃗x + v⃗ t + 1 ⃗a t 2. However once again, I am extremely confused.