Answer:
a) 2.22 %
b) Range would be 60±1.998 km/h
Step-by-step explanation:
Percentage uncertainty indicates the error of a reading. With the percentage uncertainty error for a measurement can be calculated.
a) Percentage uncertainty would be

Percent uncertainty is 2.22%
b) For 60 km/h error would be

Range would be 60±1.998 km/h