¤While jumping for a bird your cat falls off your apartment building 45 meters high (but lands in a soft pile of marshmallows of course). ¤1) How long did it take to fall? ¤2) How fast is he going when he reaches the bottom?

I dont remember which formulas were used for how long something falls and for speed.

1 Answer
Mar 16, 2017

Answer:

A....pile of marshmallows....!

Explanation:

I would suppose the vertical (downwards) initial velocity of the cat equal to zero (#v_i=0#); we can start using our general relationship:
#v_f^2=v_i^2+2a(y_f-y_i)#
where #a=g# is the acceleration of gravity (downwards) and #y# is the the height:
we get:
#v_f^2=0-2*9.8(0-45)#
#v_f=sqrt(2*9.8*45)=29.7m/s#
This will be the velocity of "impact" of the cat.

Next we can use:
#v_f=v_i+at#
where #v_f=29.7m/s# is directed downwards as the acceleration of gravity so we get:
#-29.7=0-9.8t#
#t=29.7/9.8=3s#