Problem sets for physics, please help !?

[khaayczii]

there are two ... i think these are easy ones :

1. John climbs a flight of stairs in 2mins. If he weighs 300 N and the stairs is 15 m from the ground, how much power will he develop?


2. A 20 kg iron ball is used in the shot put, has a kinetic energy of 500 J . How much momentum does it possess?

 

[Alex]

1.P=Fv=300N(15m/120)=37.5watts

2.1/2mv^2
500=1/2mv^2
1000=mv^2
50=v^2
v=7.07
p=mv=20 X 7.07=141.4