Answer: 75,242.9 m/s
Explanation:
from the question we are given the following parameters
mass of Lion (ML) = 169,169 kg
velocity of lion (VL) = 777,377.7 m/s
mass of Gazelle (Mg) = 31,731.7 kg
velocity of Gazelle (Vg) = 63,863.8 kg
mass of Lion and Gazelle (M) = 200,900.7 kg
velocity of Lion and Gazelle (V) = ?
The first figure below shows the motion of the Lion and Gazelle with their direction.
The second diagram shows the motion of the Lion and Gazelle with their directions rearranged to form a right angle triangle.
from the triangle formed we can get the velocity of the Lion and Gazelle immediately after collision using their momentum and Phytaghoras theorem
momentum = mass x velocity
momentum of the Lion = 169,169 x 77,377.3 = 13,089,840,463.7 kgm/s
momentum of the Gazelle = 31,731.7 x 63,863.8 = 2,026,506,942.46 kgm/s
momentum of the Lion and Gazelle = 200,900.7 x V
now applying Phytaghoras theorem we have
13,089,840,463.7 + 2,026,506,942.46 = 200,900.7 x V
15,116,347,406.16 = 200,900.7 x V
V = 75,242.9 m/s