Answer:
The magnitude of Daniel's velocity after collision is 6.84 m/s.
Step-by-step explanation:
Given that,
Mass of Daniel = 70.0 Kg
Mass of Rebecca = 45.0 kg
Initial speed of Rebecca= 13.0 m/s
Final speed of Rebecca = 6.00 m/s
Angle = 54.1°
Suppose we need to calculate the magnitude of Daniel's velocity after the collision
We need to calculate the velocity of Daniel along x axis
Using conservation of momentum

Put the value into the formula



We need to calculate the velocity of Daniel along y axis
Using conservation of momentum

Put the value into the formula



We need to calculate the magnitude of velocity after collision
Using formula of velocity

Put the value into the formula


Hence, The magnitude of Daniel's velocity after collision is 6.84 m/s.