It is known that the energy required to evaporate 18g sweat at 37℃ is 4320 joules.

When a classmate walks, the strength is:

36J/ 1s=36W

The strength required for a classmate to sweat and dissipate heat is:

36w-33w=3W

The amount of heat a classmate needs to emit through sweating in one hour is:

3W*3600s= 10800J

1 g sweat can dissipate heat as follows:

4320J/ 18g

The total amount of sweat required is:

10800j/(4320j/ 18g)= 45g

Students, study hard and don't answer such simple questions. . . .