K.E=0.5mv^2
GPE=mgh
The child has both K.E and GPE


g is taken as 9.81
After 3 hours.
working;
after 3 hours, Terry will have completed 15 hours + 10*3 hours=45 tasks
Susan will have completed 9+ 12*3hours= 45 tasks
Combine like terms... 2s and 4s are like terms so that's 6s 4,2,3 are like terms add that up its 9. So it would look like this 6s+9