Kelly is driving a car with a mass of 800 kilograms in a south direction with a speed of 18 meters/second. dominic is driving a truck with a mass of 1500 kilograms with a velocity of 15 meters/second to the east. they undergo perfectly inelastic collision. what is the magnitude of the final momentum of both the truck and the car.

We are given
m1 = 800 kg
v1 = 18 m/s south

m2 = 1500 kg
v2 = 15 m/s east

using the momentum balance for perfectly inelastic collision
along the x:
m1v1 + m2v2 = (m1 + m2) vx
0 + 1500 (15) = (800 + 1500) vx
vx = 9.78 m/s

along the y:
800 (-18) + 0 = (m1 + m2) vy
vy = -6.26 m/s

the magnitude is
v =  √(vx² + vy²)
v =  √( 9.78² + (-6.26)² )
v = 11.61 m/s

The reflection of the candle in the concave mirror formed an upside-down virtual image that is smaller than the candle.in other words. the answer is the third option, c

Idont understand the question