PHYSICS LAB FINAL EXAM 2025 GRADED A+
2 graduate students measure the strength of an MRI's magnetic field to have the
following value:
Student A: 4.2 +- .8 T
Student B: 5.6 +- .5 T
Do the 2 students agree for the strength of the magnetic field? - ANSWER-No
A 11600 kg railroad car is coasting on a level, frictionless track at a speed of 16.0 m/s
when a 5420 kg load is dropped onto it.
If the load is initially at rest, find the new speed of the car and the % change of the
kinetic energy. - ANSWER-10.9 m/s
Change in KE: ___%
m1*v1 + m2*v2 = (m1+m2)*V
12100*19 + (4790*0) = (12100+4790)*V
V = 13.61 m/s <---------answer
KE1 = 0.5*m1*v1^2 = 0.5*12100*19*19 = 2184050 J
KE2 = 0.5*(m1+m2)*V^2 = 0.5*(12100+4790)*13.61*13.61
KE2 = 1564285.0845 J
% change = K2-K1/K1 = (1564285.0845 - 2184050)*100/2184050 = 28.3 %
A billiard ball with mass 9.3 kg is shot due west at 4.2 m/s. The ball collides elastically
with a second billiard ball, also of mass 9.3 kg. The second billiard ball travels due west,
the same direction as the first billiard ball was traveling.
Assuming a frictionless table, what is the magnitude of the final velocity of the second
billiard ball in m/s due west? - ANSWER-4.2
2m1/m1+m2 times vo1
A block of mass m begins at rest at the top of a ramp at elevation h with whatever PE is
associated with that height.
The block slides down the ramp over a distance d until it reaches the bottom of the
ramp. How much of its original total energy (in J) survives as KE when it reaches the
ground?
, (In other words, the acceleration is not zero like it was in lab and friction does not
remove 100% of the original PE. How much of that original energy is left over after the
friction does work to remove some?) - ANSWER-ef=mgh
Eloss =umgcosthetad
ef-eloss
A car moving at some speed hits the brakes and skids to a stop after 13 m on a level
road. If the coefficient of friction for the road conditions of dry concrete is 0.50, what was
the car's original speed (in m/s) before braking? - ANSWER-v = sqrt( 2 μ g S )
A fighter pilot is exposed to an acceleration of 3g in the horizontal direction during
takeoff. Knowing that 1g=9.8 m/s2 and that the mass of the fighter pilot is 63.1 kg, what
force (in Newtons) does the fighter pilot experience in the horizontal direction? This is
the force that she feels "pressing her into the back of the seat." - ANSWER-1855
F=ma
3mg
A heavy ball collides head-on with a stationary light target elastically.
The ball: - ANSWER-continues forward
A light ball collides head-on with a stationary heavy target elastically.
The ball: - ANSWER-bounces backwards
Add the vectors A+B=C
|A|=15 N
20 degress
|B|= 11N
40 degrees - ANSWER-C = 13.5 N
at 65.2 degrees CCW
All waves that cause particles of a material to be disturbed and transfer the disturbance
to the neighboring particles by contact are this kind of wave. - ANSWER-mechanical
An ideal spring should behave ________ in its relationship between force and
displacement. - ANSWER-linearly
C=B-A
|A| = 5 m/s
25 degrees
|B|= 3 m/s
15 degrees - ANSWER-
Calculate the % change from before to after a collision if Pbefore = 0.172 and Pafter =
0.155. - ANSWER--9.88
2 graduate students measure the strength of an MRI's magnetic field to have the
following value:
Student A: 4.2 +- .8 T
Student B: 5.6 +- .5 T
Do the 2 students agree for the strength of the magnetic field? - ANSWER-No
A 11600 kg railroad car is coasting on a level, frictionless track at a speed of 16.0 m/s
when a 5420 kg load is dropped onto it.
If the load is initially at rest, find the new speed of the car and the % change of the
kinetic energy. - ANSWER-10.9 m/s
Change in KE: ___%
m1*v1 + m2*v2 = (m1+m2)*V
12100*19 + (4790*0) = (12100+4790)*V
V = 13.61 m/s <---------answer
KE1 = 0.5*m1*v1^2 = 0.5*12100*19*19 = 2184050 J
KE2 = 0.5*(m1+m2)*V^2 = 0.5*(12100+4790)*13.61*13.61
KE2 = 1564285.0845 J
% change = K2-K1/K1 = (1564285.0845 - 2184050)*100/2184050 = 28.3 %
A billiard ball with mass 9.3 kg is shot due west at 4.2 m/s. The ball collides elastically
with a second billiard ball, also of mass 9.3 kg. The second billiard ball travels due west,
the same direction as the first billiard ball was traveling.
Assuming a frictionless table, what is the magnitude of the final velocity of the second
billiard ball in m/s due west? - ANSWER-4.2
2m1/m1+m2 times vo1
A block of mass m begins at rest at the top of a ramp at elevation h with whatever PE is
associated with that height.
The block slides down the ramp over a distance d until it reaches the bottom of the
ramp. How much of its original total energy (in J) survives as KE when it reaches the
ground?
, (In other words, the acceleration is not zero like it was in lab and friction does not
remove 100% of the original PE. How much of that original energy is left over after the
friction does work to remove some?) - ANSWER-ef=mgh
Eloss =umgcosthetad
ef-eloss
A car moving at some speed hits the brakes and skids to a stop after 13 m on a level
road. If the coefficient of friction for the road conditions of dry concrete is 0.50, what was
the car's original speed (in m/s) before braking? - ANSWER-v = sqrt( 2 μ g S )
A fighter pilot is exposed to an acceleration of 3g in the horizontal direction during
takeoff. Knowing that 1g=9.8 m/s2 and that the mass of the fighter pilot is 63.1 kg, what
force (in Newtons) does the fighter pilot experience in the horizontal direction? This is
the force that she feels "pressing her into the back of the seat." - ANSWER-1855
F=ma
3mg
A heavy ball collides head-on with a stationary light target elastically.
The ball: - ANSWER-continues forward
A light ball collides head-on with a stationary heavy target elastically.
The ball: - ANSWER-bounces backwards
Add the vectors A+B=C
|A|=15 N
20 degress
|B|= 11N
40 degrees - ANSWER-C = 13.5 N
at 65.2 degrees CCW
All waves that cause particles of a material to be disturbed and transfer the disturbance
to the neighboring particles by contact are this kind of wave. - ANSWER-mechanical
An ideal spring should behave ________ in its relationship between force and
displacement. - ANSWER-linearly
C=B-A
|A| = 5 m/s
25 degrees
|B|= 3 m/s
15 degrees - ANSWER-
Calculate the % change from before to after a collision if Pbefore = 0.172 and Pafter =
0.155. - ANSWER--9.88
