Question

Your little dog, Fluffy, is excited to see you and jumps straight up in the air to a height of 0.680 m . What is Fluffy's initial speed as she leaves the ground? You can assume that Fluffy is in "Free Fall" (constant acceleration) during the jump.

v =

3.65

m/s

Correct

Part B

What is the length of time that Fluffy is in the air?

Answer 1

Solution-

Height h = 0.680m
So the displacement of the Fluffy S = 0.68 m
Accleration a = -g
                     = -9.8 m / s ^ 2
Iinitial speed of the Fluffy u = ?
final speed i.e., speed at maximum height   is v = 0 m / s
from the relation v ^ 2 - u ^ 2 = 2aS
                                  - u ^ 2 = 2 ( -g ) S
                                           u= √[ 2 gS ]
                                            = 3.65 m / s
(b). time the flea in air = time of scent + time ofdecent
                                  = ( u / g ) + ( u / g )
                                  = 2u / g

=2*3.65/9.81

                                  = 0.744 s