A model rocket with a mass of 2.7kg is launched straight up from the ground at a speed of 110m/s. What is its mechanical energy at the maximum height?

1 Answer
Nov 14, 2015

Answer:

I found: #16335J#

Explanation:

At maximum height velocity will be zero so Kinetic Energy will also be zero. Mechanical Energy will be given entirely by Gravitational Potential Energy #U=mgh#.

To find #h# we use the relationship:

#v_f^2=v_i^2+2ah#

where:
#v_f=# final velocity#=0#;
#v_i=# initial velocity #=110m/s#;
#a=-g# acceleration of gravity #=-9.8m/s^2# negative because directed downwards;

So:
#110^2=0^2-2*9.8h#
#h=617m#
And:
#U=2.7*9.8*617=16335J~~16KJ#