What is the kinetic energy of an object with a mass of #3 kg# that has been in freefall for #6 s#?

1 Answer
Jan 31, 2016

I found #5,186J#

Explanation:

the object will fall from a height given as:
#y_f-y_i=v_it+1/2at^2#
where:
#y_f=0# the ground;
#y_i=h# is the height from which the object is falling;
#v_i=0# the initial velocity;
#t# is the time;
#a# is the acceleration of gravity.
We then get:
#-y_i=-1/2*9.8*(6^2)#
so #y_i=176.4m#
When the object falls potential energy #U=mgh# is converted into Kinetic Energy #K#.
so::
#U=3*9.8*176.4=5,186J# that will be our kinetic energy.