1. An ice skater glides slowly to a stop
Let’s talk about the time in a graceful move.

2. The question Sasha Cohen glides on her ice skates
from an initial speed of 2m/s
to a stop. Her acceleration
is m/(s*s). How long does her glide take?
a. 1; b. 2; c. 4; d. 6; e. 8 (seconds)

3. Guide: Sketch Units List variables: Phys Eqn. : Algebra: Arithmetic:
Answer letter: e.
Comment: a piece of cake.
v=x/t
a=(v-vo)/t
x=vo*t+at2/2
v2=vo2+2ax

4. Prof’s step by step answer
Sketch (units ok):
Units OK
List variables: vo, v, a, t=?
Phys Eqn. : a=(v-vo)/t
Algebra: a=-vo/t; t=-vo/a
Arithmetic: t=-2/(-1/4)=8s
Answer letter: e.
Comment: a piece of cake.
Vo=2m/s
V=0
t=0 t=?
v=x/t
a=(v-vo)/t
x=vo*t+at2/2
v2=vo2+2ax