Final Phys 103 – 95 pts
9 November 2011
Name______________________________
Equations:
Heat: Q = mcΔT
Hooke’s Law: F = kx
Resultant: R2 = Rx2 + Ry2
Tan θ= Ry/Rx
Practical Questions
1) (5 pts) Measure the length of the provided cylinder with the vernier caliper.
Length = _____________ cm
2) (10 pts) Determine the mass of the aluminum cylinder with the provided materials. Assume all the
clips have equal mass. Draw a figure and/or show any data or calculations for full credit.
Mass of cylinder =______________g
3) (10 pts) Place 150 g on the spring, including the hanger. Set the spring in motion. Measure the period
of the mass on the spring. Show any data or calculations for full credit.
Multiple Choice – Circle the Correct Answer (2 points each)
4) Which of these forces provides the centripetal force for a ball being twirled in a circle?
a.
b.
the gravitational force
the tension force
c.
d.
the torque
the normal force
5) You want to see-saw with your (much larger) Cousin Jimbo. You sit on the seat of the seesaw. Where
should Cousin Jimbo sit to make this easier?
a.
b.
on the same side as you
on the other seat
c.
d.
at the pivot point
closer to the pivot point
6) A spring is described by a spring constant of 10 N/m. It is compressed from equilibrium by 0.5 m.
What is the magnitude of the force required to compress the spring?
a.
b.
0.2 N
50 N
c.
d.
5N
20 N
7) A material has a density of 1200 kg/m3. It has a volume of 0.2 m3. What is its mass?
a.
b.
240 kg
44 kg
c.
d.
6,000 kg
0.00017 kg
8) A material with a higher specific heat (compared to one of lower specific heat)…
a.
b.
has a bigger mass
requires more energy to raise its
temperature for the same mass
c.
d.
is more dense
requires less energy to raise its
temperature for the same mass
Short Answer
9) (10 pts) Using trigonometry (component method) or a graphical method, calculate the sum of these
two vectors. Show your work.
A = 10 N at 90°
B = 15 N at 40°
10) (5 pts) As we set up in lab, a cart of mass, m, is on an inclined plane of angle, θ . The cart is attached
to a sting, pulley and weight that apply a force, F, up the plane. Draw a force diagram or figure showing
all the forces on the cart if it is traveling DOWN the plane at a constant velocity. Label all forces.
11) (10 pts) You combine 50 g of copper shot initially at 100°C with 100 g of water at 20°C. The final
equilibrium temperature is 30°C. The specific heat of water is 1 cal/(g °C). What is the specific heat, c, of
copper? Show your calculations.
12) (5 pts) What are the period and radius of motion for this object traveling in a circular path? The
displacement versus time is graphed in this figure:
Simple Harmonic Motion (x vs. t)
Displacement (meters)
4
3
2
1
0
-1
-2
-3
-4
0
1
2
3
4
5
6
7
8
time (seconds)
9
10
11
12
13
14
13) (10 pts) Determine the spring constant, k, from the graph. The equation of the line is:
T2 = (4π2/k) (ml + mh +fms), where ml is the mass of the load, mh is the mass of the hanger, and
ms is the mass of the spring.
Period Squared, T 2 (s2)
1.2
1
0.8
0.6
0.4
0.2
0
0
0.05
0.1
0.15
0.2
0.25
Mass, m l + m h (kg)
14) (20 pts) The following data were taken for the surface area of a sphere, which is represented by this
equation:
A = 4πr2
Plot the data (so that it is linear) on the graph paper and interpret it appropriately to determine the
value for π.
The actual value for π is 3.14. Compute the percent difference between your experimental value (from
the graph) and the actual value. Show your calculations for full credit.
Area
(m2)
3
10
30
50
radius
(m)
0.5
1
1.5
2