On number 5 circuit 15amp breaker trips off. The rest of the 15amp circuit breakers are okay. Could this breaker have a weak spring?

You can try swapping the circuit wire to another breaker to see if the problem is the circuit or the breaker. If the breaker still trips with another circuit, change the breaker. If not, get back here, as there must be a problem with the circuit or something plugged into the circuit.