A 70.7kg high jumper leavs the ground with a vertical velocity of 6.2 m/s. The acceleration of gravity is 9.8m/s^2.
How high can she jump? Answer in units of m.
THANKS!
2007-12-15 05:43:03 · 3 answers · asked by Jordan K ® 3 in Science & Mathematics ➔ Physics
2 a h = v²
You know a and v; plug them in and solve for h.
2007-12-15 05:46:50 · answer #1 · answered by jgoulden 7 · 0⤊ 0⤋
The problem can be solved equating the initial kinetic energy of the jumper of mass m (and not height!) and speed u with its final potential energy in the gravitational field g at a height h i.e.
muu/2=mgh
where from you obtain
h=uu/2g==(6.2)^2/9.81=4,44 m
As you can see it is not necessary to know the mass of the jumper!
2007-12-15 18:13:31 · answer #2 · answered by Anonymous · 0⤊ 0⤋
V²=2as + U²
V =0
a = -9.8
s=??
U = 6.2
0=2(-9.8)s+(6.2)²
s=1.96122449 m
or
K.E=G.P.E
1/2 x mass x V² = mass x gravity accelration x height
1/2 x 70.7 x (6.2)² = 70.7 x 9.8 x height
height = 1.96122449 m
2007-12-15 05:55:34 · answer #3 · answered by Murtaza 6 · 0⤊ 0⤋