PHYS 250 Exam 3 And 4 Questions
and All Correct Answers.
Two children, Ahmed and Jacques, ride on a merry-go-round. Ahmed is at a greater distance
from the axis of rotation than Jacques. Which of the following are true statements?
a. Jacques has a greater angular speed than Ahmed.
b. Jacques and Ahmed have the same angular speed
c. Jacques has a smaller angular speed than Ahmed
d. Jacques and Ahmed have the same tangential speed - Answer b
The figure shows scale drawings of four objects, each of the same mass and uniform thickness,
with the mass distributed uniformly. Which one has the greatest moment of inertia when
rotated about an axis perpendicular to the plane of the drawing at point P? (This is a conceptual
questions. No calculation or formula is needed.)
A
B
C
D - Answer b
A rubber ball and a lump of clay have equal mass. They are thrown with equal speed against a
wall. The ball bounces back with nearly the same speed with which it hit. The clay sticks to the
wall. Which one of these objects experiences the greater momentum change?
a. Both of them experience the same non-zero momentum change
b. Both of them experience zero momentum change
c. the ball
d. the clay - Answer d
When a car is weighed, it is driven slowly on a horizontal floor over a scale that records a
reading as the front wheels go over the scale, and then records a second reading as the rear
wheels go over the scale. The weight of the car is equal to
a. the weight under the front wheels
b. the difference of the 2 weights
c. the sum of the 2 weights
d. the average of the 2 weights - Answer c
During World War I, Germany used a "Big Bertha" cannon to hurl shells into Paris 30 miles away.
This gun also had a very long barrel. What was the reason for using a long barrel in these guns?
, a. exert a larger force
b. to reduce frictional losses
c. to reduce the force exerted on the bullet due to the expanding gases from the gunpowder
d. to allow the force of the expanding gases from the gunpowder to act for a longer time -
Answer d
Identical forces act for the same length of time on two different objects. The magnitude of the
change in momentum of the lighter object is
a. exactly equal to the magnitude of the change in momentum of the larger mass
b. There is not enough information to answer the question
c. 0
d. smaller than the magnitude of the change in momentum of the larger mass, but not zero
e. larger than the magnitude of the change in momentum of the larger mass - Answer a
A small car meshes with a large truck in a head-on collision. Which of the following statements
concerning the magnitude of the average force during the collision is correct?
a. The small car and the truck experience the same average force
b. The truck experiences the greater average force
c. The force experienced by each one is inversely proportional to its mass
d. The small car experiences the greater average force
e. The force experienced by each one is directly proportional to its mass - Answer a
Which of the following quantities are units of impulse?
a. kg*m2/s2
b. Ns
c. kg*s/m
d. Nm - Answer b
A diatomic molecule is oriented as follows along the x-axis: mass m is at the origin and mass 2m
is at x = a. What is the moment of inertia of this molecule about the y-axis?
a. 3ma^2
b. 0
c. ma^2
d. 2ma^2 - Answer d
and All Correct Answers.
Two children, Ahmed and Jacques, ride on a merry-go-round. Ahmed is at a greater distance
from the axis of rotation than Jacques. Which of the following are true statements?
a. Jacques has a greater angular speed than Ahmed.
b. Jacques and Ahmed have the same angular speed
c. Jacques has a smaller angular speed than Ahmed
d. Jacques and Ahmed have the same tangential speed - Answer b
The figure shows scale drawings of four objects, each of the same mass and uniform thickness,
with the mass distributed uniformly. Which one has the greatest moment of inertia when
rotated about an axis perpendicular to the plane of the drawing at point P? (This is a conceptual
questions. No calculation or formula is needed.)
A
B
C
D - Answer b
A rubber ball and a lump of clay have equal mass. They are thrown with equal speed against a
wall. The ball bounces back with nearly the same speed with which it hit. The clay sticks to the
wall. Which one of these objects experiences the greater momentum change?
a. Both of them experience the same non-zero momentum change
b. Both of them experience zero momentum change
c. the ball
d. the clay - Answer d
When a car is weighed, it is driven slowly on a horizontal floor over a scale that records a
reading as the front wheels go over the scale, and then records a second reading as the rear
wheels go over the scale. The weight of the car is equal to
a. the weight under the front wheels
b. the difference of the 2 weights
c. the sum of the 2 weights
d. the average of the 2 weights - Answer c
During World War I, Germany used a "Big Bertha" cannon to hurl shells into Paris 30 miles away.
This gun also had a very long barrel. What was the reason for using a long barrel in these guns?
, a. exert a larger force
b. to reduce frictional losses
c. to reduce the force exerted on the bullet due to the expanding gases from the gunpowder
d. to allow the force of the expanding gases from the gunpowder to act for a longer time -
Answer d
Identical forces act for the same length of time on two different objects. The magnitude of the
change in momentum of the lighter object is
a. exactly equal to the magnitude of the change in momentum of the larger mass
b. There is not enough information to answer the question
c. 0
d. smaller than the magnitude of the change in momentum of the larger mass, but not zero
e. larger than the magnitude of the change in momentum of the larger mass - Answer a
A small car meshes with a large truck in a head-on collision. Which of the following statements
concerning the magnitude of the average force during the collision is correct?
a. The small car and the truck experience the same average force
b. The truck experiences the greater average force
c. The force experienced by each one is inversely proportional to its mass
d. The small car experiences the greater average force
e. The force experienced by each one is directly proportional to its mass - Answer a
Which of the following quantities are units of impulse?
a. kg*m2/s2
b. Ns
c. kg*s/m
d. Nm - Answer b
A diatomic molecule is oriented as follows along the x-axis: mass m is at the origin and mass 2m
is at x = a. What is the moment of inertia of this molecule about the y-axis?
a. 3ma^2
b. 0
c. ma^2
d. 2ma^2 - Answer d
