A body of mass m is thrown at an angle alpha to the horizontal with the initial velocity v0. Find the mean power developed by gravity over the whole time of motion of the body, and the instantaneous power of gravity as a function of time.(adsbygoogle = window.adsbygoogle || []).push({});

I didn't understand whydelta ris orthogonal to mg. Where delta r is the net displacement of the body during time of flight.

**Physics Forums | Science Articles, Homework Help, Discussion**

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Homework Help: Irodov Problem

**Physics Forums | Science Articles, Homework Help, Discussion**