How long is the flea in the air from the time it jumps to the time it hits the ground?

Question

In this problem, you will apply kinematic equations to a jumping flea. Take the magnitude of free-fall acceleration to be 9.80 m/s^2. A flea jumps straight up to a maximum height of 0.430 m. How long is the flea in the air from the time it jumps to the time it hits the ground?

Answer 1

Use s = u t + 1/2 a t^2

0.430 = 0 + 1/2 x 9.8 x t^2

0.860 / 9.8 = t^2

t = 0.29623 seconds (this is for the way up)

It takes the same time to come back down, therefore-:

2 x 0.29623 = 0.59246 seconds (for the total journey)

Well done Mr. Flea !!! ;o)

Answer 2

You are on the right track
consider

h=.5gt^2
h = 0.430 m

so t = sqrt(2h/g)
hower it is the time for the flea to fall down from height h and it takes the same amount of time to go up as it is to come down.
t(total)=2t
finaly we have
t(total)=2sqrt(2h/g)

t(total) 2 sqrt(2 x 0..430 /9.80)
t(total)=0.59 sec