Game Development Reference
In-Depth Information
2.
The time it will take for the object to reach the ground can be found from Equation (5.8c).
2
d
4
s
t
=
=
=
0.639
g
9.81
The velocity when the object strikes the ground is equal to the product of the gravita-
tional acceleration and the time.
m/s
v t
==−
9.81* 0.639
=−
6.26
Because the object is striking the ground vertically, its rebound velocity is equal to the
impact velocity multiplied by the coefficient of restitution.
m/s
′
==−
v
ev
0.9 * (
−
6.26)
=
5.63
z
z
The time it takes the object to reach the apex of its bounce is 5.63/9.81 = 0.574
s
. The
height that the object will reach at its apex can now be computed.
1
9.81 0.574
(
)
m
2
z
=−
+
5.63* 0.574
=
1.62
2
3.
There is no net torque acting on the skater because gravity is acting along the axis of
rotation. Therefore the angular momentum of the skater is conserved as she draws her
arms inward.
I
ω
=
cons
tan
t
=
2.0
* (2.0 *2
p
)
=
1.6
(
θ
*2
p
)
Here new rotation speed is = 2.5
rev/s
.
