Final answer:
The mass of the bicycle is 9 kg and the combined mass of the student and bicycle is 64 kg.
Step-by-step explanation:
The momentum of an object can be calculated by multiplying its mass by its velocity. In this case, the momentum of the bicycle and rider is given as 320 kg•m/s. Let's denote the mass of the bicycle as m1 and the mass of the rider as m2. We can set up the following equations:
m1v1 + m2v2 = p (Equation 1)
where v1 is the velocity of the bicycle, v2 is the velocity of the rider, and p is the momentum.
We are given that the rider has a mass of 55 kg and the velocity of the bicycle and rider is 5.0 m/s. Let's substitute these values into Equation 1:
m1(5.0 m/s) + (55 kg)(5.0 m/s) = 320 kg•m/s
Simplifying this equation, we have:
5.0m1 + 275 = 320
Subtracting 275 from both sides, we have:
5m1 = 45
Dividing both sides by 5, we find that the mass of the bicycle is 9 kg.
To find the combined mass of the student and bicycle, we simply add the mass of the student (55 kg) to the mass of the bicycle (9 kg). The combined mass is therefore 64 kg.