Straighter Line Physics (New Version August
2024) Scored 100%
When a small car pulls a trailer for a move, which of the following explains why the
trailer moves? - ANSWER While the force of the trailer on the car is equal and
opposite to the force of the car on the trailer, the total of all forces acting on the car
are unbalanced.
Suppose you are driving a car at a constant speed of 40 mph in a straight line. All of
a sudden the road curves to the right but you manage to keep driving at exactly the
same speed. Which of the following statements is correct? - ANSWER There was
a net force acting on the car.
Given the vectors C=2i^+7j^ and D=14i^+38j^D, find the angle θ between them. -
ANSWER θ=4∘
Match each of the following descriptions of motion with the appropriate graph.
resting
uniform motion
accelerated motion
oscillating motion - ANSWER 1-B; 2-D; 3-C; 4-A
A juggler is juggling 3 balls. If she throws them 2.4 m in the air at an angle of 80°
relative to the horizontal, what is the time between throws? (You should ignore air
drag and the time it takes for the juggler to move balls from one hand to the other.) -
ANSWER 0.47 s
Given the vectors C=1.5i^+6.2j^ and D=4.4i^+7.3j^, calculate the magnitude of their
vector product. - ANSWER 16.3
Which of the following statements concerning friction between the surfaces of two
objects is correct? - ANSWER The force of friction mostly depends on the nature of
the two surfaces.
,A 2.5 kg object is suspended from a spring with a spring constant of 48 N / m. The
mass is pulled 0.25 m downward from its equilibrium position and released. Which of
the following is the maximum kinetic energy of the object? - ANSWER 1.5 J
Why is (vector) A⋅ (vector) B =AxBx+AyBy - ANSWER All the cross-terms are
equal to zero.
Consider a mass m that is attached to a rope such that the mass is in uniform
circular motion. Which of the following is the magnitude of the centripetal force? -
ANSWER mv 2/r
Which of the following applies to the tangential velocity v of uniform circular motion?
- ANSWER constant speed but not constant velocity
If the cross product of a vector of length 5 and a vector of length 3 results in a vector
of length 10, what is the angle between them? - ANSWER 42°
Which of the following is not a vector? - ANSWER 2 kg of mass under a table
The Ideal Gas law is given by which equation? (n is the number of moles of the gas)
- ANSWER PV = nRT
Two vectors can be added graphically by __________. - ANSWER adding them tip
to tail
Consider a rectangle with a base of 0.567 m and a height of 1.606 m. What is its
area? - ANSWER 0.911 m2
A mass of 5.2 kg is accelerated to 4.0 m / s2 when a force of magnitude F is applied
to it. If the same force is applied to another object causes it have an acceleration of
1.8 m / s2, what is the mass of this object? - ANSWER 12 kg
The equation for torque is given by τ=F×dτ where F is a force applied at a distance
d→ from the axis of rotation. Which of the following is the magnitude of torque
resulting from a 2.4 N force applied 17 cm from the point of rotation if the force is
applied at a 45∘ angle to the displacement vector? - ANSWER 0.29 N⋅m
Which is the definition of a derived unit? - ANSWER A unit which is based on other
(basic) units.
Which is not a basic unit? - ANSWER velocity
What would happen to the precession of a gyroscope if it were spinning in the
opposite direction? - ANSWER It would precess in the opposite direction.
A 0.500 kg steel ball is dropped from a height of 4.00 m onto a horizontal steel slab.
The collision appears elastic in that the ball rebounds to its original height. If the
collision lasts for 2.00 × 10−3 s, which of the following is the impulse imparted to the
ball and the average force applied to the ball during the collision? - ANSWER I =
8.85 kg•m / s
, F = 4.43 × 103 N
A 2.6 cm × 5.2 cm domino of mass 18 g is set in the position shown and released.
Taking the domino to be a uniform rectangle plate, what is its angular acceleration
about the corner that rests on the surface? The moment of inertia of a uniform
rectangular plate with side lengths a and b about an axis running perpendicular to it
and through its center is I=112M(a2+b2) - ANSWER 41rad/s2
Would an object precess faster if it had more angular momentum? - ANSWER No,
because the angular velocity of precession is inversely proportional to the magnitude
of the gyroscope's angular momentum
A mass-spring system has an amplitude of0.820 m and a period of 0.690 s. If the
mass attached is 0.500 kg, what is the acceleration at half the amplitude? -
ANSWER 34.0m/s2
A 0.200 kg dart is fired horizontally at a speed of 2.75 m / s when it hits a 0.700 kg
block of wood suspended by a string. The nose of the dart sticks into 0.00210 m the
wood. Together the dart and block swing upwards from a height of 0.0500 m above a
table to 0.128 m above the table. Which of the following is the average force the dart
applies to the block during impact? - ANSWER 32.4 N
A 16 lb bowling ball is resting in an angled crook, as shown. What is the force
exerted on the ball by the right-hand surface? 1 Newton is equivalent to 0.225 lb. -
ANSWER 68 N
An empty freight train car of mass 10,000 kg is rolling along a level section of track at
2.00 m / s. It collides with a loaded car of weight 1.96 × 105 N, which is at rest. The
cars couple upon collision. Which of the following is the speed of the train after the
collision? - ANSWER 0.667 m / s
A 1,450 kg car moves with a speed of 25.0 m / s when it collides with a stationary car
having a mass of 1,550 kg. The two vehicles lock bumpers on impact. The two cars
then collide with a stationary third car of mass 1,250 kg. During this second impact,
the third vehicle becomes attached to the second but the first car is breaks free and
moves at 0.125 m / s in the opposite direction. Which of the following is the final
velocity of the second and third cars after the final collision? - ANSWER 13.01 m /
s
Tom and Joe are trying to fly a new style of kite that they have invented. Both of
them are holding strings attached to the kite. The tension in each string is 126 N.
The angle between the strings is 36°. Unfortunately, the kite will not rise in the air,
and the strings held by Tom and Joe are essentially parallel to the ground. Tom and
Joe have run a distance of 100 m trying to get the kite to fly. How much work have
they done on the kite? - ANSWER 24,000 N • m
A spaceship is in space and currently at rest. The directive is given to accelerate
from rest to a speed of 2.90 × 103 m / s. If the fuel budgeted for this action is 400 kg,
which of the following is velocity of the exhaust gas required if the ship mass is 7.38
×103 kg? - ANSWER -5.5 × 104 [m / s]
2024) Scored 100%
When a small car pulls a trailer for a move, which of the following explains why the
trailer moves? - ANSWER While the force of the trailer on the car is equal and
opposite to the force of the car on the trailer, the total of all forces acting on the car
are unbalanced.
Suppose you are driving a car at a constant speed of 40 mph in a straight line. All of
a sudden the road curves to the right but you manage to keep driving at exactly the
same speed. Which of the following statements is correct? - ANSWER There was
a net force acting on the car.
Given the vectors C=2i^+7j^ and D=14i^+38j^D, find the angle θ between them. -
ANSWER θ=4∘
Match each of the following descriptions of motion with the appropriate graph.
resting
uniform motion
accelerated motion
oscillating motion - ANSWER 1-B; 2-D; 3-C; 4-A
A juggler is juggling 3 balls. If she throws them 2.4 m in the air at an angle of 80°
relative to the horizontal, what is the time between throws? (You should ignore air
drag and the time it takes for the juggler to move balls from one hand to the other.) -
ANSWER 0.47 s
Given the vectors C=1.5i^+6.2j^ and D=4.4i^+7.3j^, calculate the magnitude of their
vector product. - ANSWER 16.3
Which of the following statements concerning friction between the surfaces of two
objects is correct? - ANSWER The force of friction mostly depends on the nature of
the two surfaces.
,A 2.5 kg object is suspended from a spring with a spring constant of 48 N / m. The
mass is pulled 0.25 m downward from its equilibrium position and released. Which of
the following is the maximum kinetic energy of the object? - ANSWER 1.5 J
Why is (vector) A⋅ (vector) B =AxBx+AyBy - ANSWER All the cross-terms are
equal to zero.
Consider a mass m that is attached to a rope such that the mass is in uniform
circular motion. Which of the following is the magnitude of the centripetal force? -
ANSWER mv 2/r
Which of the following applies to the tangential velocity v of uniform circular motion?
- ANSWER constant speed but not constant velocity
If the cross product of a vector of length 5 and a vector of length 3 results in a vector
of length 10, what is the angle between them? - ANSWER 42°
Which of the following is not a vector? - ANSWER 2 kg of mass under a table
The Ideal Gas law is given by which equation? (n is the number of moles of the gas)
- ANSWER PV = nRT
Two vectors can be added graphically by __________. - ANSWER adding them tip
to tail
Consider a rectangle with a base of 0.567 m and a height of 1.606 m. What is its
area? - ANSWER 0.911 m2
A mass of 5.2 kg is accelerated to 4.0 m / s2 when a force of magnitude F is applied
to it. If the same force is applied to another object causes it have an acceleration of
1.8 m / s2, what is the mass of this object? - ANSWER 12 kg
The equation for torque is given by τ=F×dτ where F is a force applied at a distance
d→ from the axis of rotation. Which of the following is the magnitude of torque
resulting from a 2.4 N force applied 17 cm from the point of rotation if the force is
applied at a 45∘ angle to the displacement vector? - ANSWER 0.29 N⋅m
Which is the definition of a derived unit? - ANSWER A unit which is based on other
(basic) units.
Which is not a basic unit? - ANSWER velocity
What would happen to the precession of a gyroscope if it were spinning in the
opposite direction? - ANSWER It would precess in the opposite direction.
A 0.500 kg steel ball is dropped from a height of 4.00 m onto a horizontal steel slab.
The collision appears elastic in that the ball rebounds to its original height. If the
collision lasts for 2.00 × 10−3 s, which of the following is the impulse imparted to the
ball and the average force applied to the ball during the collision? - ANSWER I =
8.85 kg•m / s
, F = 4.43 × 103 N
A 2.6 cm × 5.2 cm domino of mass 18 g is set in the position shown and released.
Taking the domino to be a uniform rectangle plate, what is its angular acceleration
about the corner that rests on the surface? The moment of inertia of a uniform
rectangular plate with side lengths a and b about an axis running perpendicular to it
and through its center is I=112M(a2+b2) - ANSWER 41rad/s2
Would an object precess faster if it had more angular momentum? - ANSWER No,
because the angular velocity of precession is inversely proportional to the magnitude
of the gyroscope's angular momentum
A mass-spring system has an amplitude of0.820 m and a period of 0.690 s. If the
mass attached is 0.500 kg, what is the acceleration at half the amplitude? -
ANSWER 34.0m/s2
A 0.200 kg dart is fired horizontally at a speed of 2.75 m / s when it hits a 0.700 kg
block of wood suspended by a string. The nose of the dart sticks into 0.00210 m the
wood. Together the dart and block swing upwards from a height of 0.0500 m above a
table to 0.128 m above the table. Which of the following is the average force the dart
applies to the block during impact? - ANSWER 32.4 N
A 16 lb bowling ball is resting in an angled crook, as shown. What is the force
exerted on the ball by the right-hand surface? 1 Newton is equivalent to 0.225 lb. -
ANSWER 68 N
An empty freight train car of mass 10,000 kg is rolling along a level section of track at
2.00 m / s. It collides with a loaded car of weight 1.96 × 105 N, which is at rest. The
cars couple upon collision. Which of the following is the speed of the train after the
collision? - ANSWER 0.667 m / s
A 1,450 kg car moves with a speed of 25.0 m / s when it collides with a stationary car
having a mass of 1,550 kg. The two vehicles lock bumpers on impact. The two cars
then collide with a stationary third car of mass 1,250 kg. During this second impact,
the third vehicle becomes attached to the second but the first car is breaks free and
moves at 0.125 m / s in the opposite direction. Which of the following is the final
velocity of the second and third cars after the final collision? - ANSWER 13.01 m /
s
Tom and Joe are trying to fly a new style of kite that they have invented. Both of
them are holding strings attached to the kite. The tension in each string is 126 N.
The angle between the strings is 36°. Unfortunately, the kite will not rise in the air,
and the strings held by Tom and Joe are essentially parallel to the ground. Tom and
Joe have run a distance of 100 m trying to get the kite to fly. How much work have
they done on the kite? - ANSWER 24,000 N • m
A spaceship is in space and currently at rest. The directive is given to accelerate
from rest to a speed of 2.90 × 103 m / s. If the fuel budgeted for this action is 400 kg,
which of the following is velocity of the exhaust gas required if the ship mass is 7.38
×103 kg? - ANSWER -5.5 × 104 [m / s]
