PHY131 MidtermI
Practice Exam Solutions
1) The punter on a football team tries to kick a football so that it stays in the air a long time, the
socalled “hang time”. The ball is kicked with an initial velocity of
25.0 m/s at an angle of 60
o
relative to the ground.
a) What is the “hang time”?
b) What is the distance the ball is in air before it hits the ground
again?
a) hang time:
s
g
v
g
v
t
gt
v
gt
t
v
t
y
y
y
y
42
.
4
sin
2
2
2
1
0
2
1
)
(
0
0
0
2
0
=
=
=
⇒
=
⇒
=
−
=
θ
y
x
θ
v
0
b) distance in air:
m
g
v
g
v
v
t
v
t
x
x
2
.
55
cos
sin
2
sin
2
cos
)
(
2
0
0
0
0
=
=
=
=
2) A Ferris wheel with radius R = 14.0 m is turning counter clockwise about a horizontal axis
through its center. The speed of the seats on the rim is constant at 7.00 m/s. An 80kg
passenger is sitting on a bathroom scale.
a) What will the scale read at the highest point of the circular motion?
b) What will it read at the lowest point?
a) at highest point:
This preview has intentionally blurred sections. Sign up to view the full version.
View Full Document
This is the end of the preview.
Sign up
to
access the rest of the document.
 Spring '03
 Rijssenbeek
 Physics, Mass, Velocity, Trigraph, fn fn, mg cos FT

Click to edit the document details