An iron ball rolls off a cliff which is 23.3 m high and lands on your new car. Assume your car is 2.3 m tall. How fast was the iron ball traveling just before it hit your car in m/s?
1 Answer
Explanation:
We're asked to find the speed of the ball just before it comes in contact with a car, given the height at which it began free fall and the height it hit the car.
To do this, we can use the equation
where
-
the final
#y# -velocity#v_y# is what we're trying to find -
the initial
#y# -velocity#v_(0y)# is#0# , because it simply dropped on its own to start its free fall -
the
#y# -acceleration#a_y# is#-g# , which is#-9.81# #"m/s"^2# -
the final position
#y# is#2.3# #"m"# -
the initial position
#y_0# is#23.3# #"m"#
Plugging in known values, we have
rounded to