Physics quiz's [ chapter 1-5]

The units gal/h can be converted to which of the following units? (i) m/s (ii) cm/s^2 (iii) mm^3 /y (iv) liters/acre

(iii) mm^3 /y

Which of the following expresses 5.2 x 10-5 s correctly using the metric prefixes given?

0.52ms

Which of the following are reasonable values for the magnitude of a vector? (i) 0 (ii) -1 (iii) +1

1 and 3

Determine which of the following objects obey the equations of projectile motion developed in this chapter. i. A ball is thrown in an arbitrary direction. ii. A jet airplane crosses the sky with its engines thrusting the plane forward. iii. A rocket leaves the launch pad. iv. A rocket moving through the sky after its engines have failed. v. A stone is thrown underwater

1 and 4

You go out for a burger with some friends. At the restaurant the waiter serves you your burger on a plate. You pick up the burger with your hand and lift it to your mouth. This action requires about ________ of work.

1 joules

You go out for a burger with some friends. At the restaurant the waiter serves you your burger on a plate. You pick up the burger with your hand and lift it to your mouth. About how much power did you expend when you lifted the burger to your mouth from the plate?

1 watts

Suppose that you measure the position of a chair using a meter stick and you record the distance of the center of the seat from the wall. Which of the following measurements is the most reasonable?

1.04m

Within what percentage of the correct value would you expect an order-of-magnitude calculation to result?

10%

Rank the launch angles for the five paths in the figure below with respect to the time of flight, from the shortest time of flight to the longest.

15°, 30°, 45°, 60°, 75°

Suppose that two quantities, A and B, have DIFFERENT dimensions/units. Determine which of the following arithmetic operations could be physically meaningful. (i) A + B (ii) A/B (iii) B - A (iv) AB

2 and 4

Two nonzero vectors have unequal magnitudes of X and Y. Which of the following could be the length of their sum? (i) 0 (ii) X+Y (iii) X (iv) Y

2,3 and 4

Which of these numbers is closest to the number of barbers in the US?

200,000

You push an object, initially at rest, across a frictionless floor with a constant force for a time interval, Δt, which results in a final speed of v for the object. You repeat the experiment, but with a force that is half as large. What time interval is now required to reach the same final speed?

2Δt

If 3 different conservative forces and one non-conservative force act within a system, how many potential energy terms appear in the energy equation that describes the system?

3

Which of the following are vectors? (i) your age (ii) your height (iii) acceleration (iv) velocity (v) speed (vi) mass

3 and 4

The magnitudes of two vectors A → and B → are A = 5 units and B = 2 units. Select the largest and smallest values for the magnitude of the resultant vector, A → + B → .

3 and 7

If the numbers 12.345 and 5.67 are multiplied, divided, added, or subtracted, how many significant figures result in each case?

3,3,4,3

A right triangle has sides 5 m, 12 m, and 13 m.  What is the sine of the smallest angle of this triangle?

5/13

An older model car accelerates from rest to speed v in 10 seconds. A newer, more powerful sports car accelerates from rest to speed 2v in half the time (5 seconds). What is the ratio of the power of the newer car to that of the older car?

8.0

Under which of the following conditions is the magnitude of the average velocity of a particle moving in one dimension smaller than the average speed over the time interval? -A particle moves in the -x direction without reversing -A particle moves in the +x direction and then reverses the direction of its motion -There are no conditions for which this is true -A particle moves in the +x direction without reversing

A particle moves in the +x direction and then reverses the direction of its motion

An object moves with a constant velocity. Which of the following CANNOT be true for the object?

A single force acts on the object

A race car moving quickly around a track collides with a mosquito, which splatters on the car's windshield. Which object experiences a greater magnitude impact force?

Both experience the same force

Consider the following two statements and then select the option below that is correct: i. It is possible for an object to move in the absence of forces acting on the object. ii. It is possible to have forces acting on an object in the absence of motion of the object.

Both statements are correct

which of the following is true?

Dimensional analysis can NEVER give you the numerical value of constants of proportionality that may appear in an algebraic expression, but it can sometimes give the proper mathematical forms for the variables (such as whether they are squared, multiplied by each other, divided by each other, added together, or subtracted from each other).

A certain uniform spring has a constant k. Now the spring is cut in half. What is the relationship between k and the spring constant k' of each resulting smaller spring?

Each k' = 2k

A block of mass m is projected across a horizontal surface with an initial speed v. It slides until it stops due to the friction force between the block and the surface. The same block is now projected across the horizontal surface with an initial speed v/2. When the block has come to rest, how does the distance from the projection point compare to that in the first case?

It is one fourth as large

Discuss whether any work is being done by each of the following agents and, if so, whether the work is positive or negative. (i) a chicken scratching on the ground (ii) a person studying physics (iii) a crane lifting a bucket of concrete (iv) the gravitational force on the bucket in (v) the leg muscles of a person in the act of sitting down

No work is done in case (ii). Positive work is done in cases (i) and (iii) and negative work is done in cases (iv) and (v).

Consider two slides, both of the same height. One is long and the other is short. From which slide will a child have a greater final speed when sliding off? Assume that there is no friction acting

The final speed will be the same for the child on the longer slide as it is for the children on the shorter slide

An object accelerates when it experiences a non-zero net force. Which of the following statements is always true?

The object's acceleration is in the same direction as the net force that acts upon it

Suppose that the component of A → along the direction of B → is zero. What can you conclude about the two vectors?

They are parallel and in the same direction

Jordan throws a marble upward with a speed vi , while Marisa drops a marble at the same instant. While they are in flight, which of the following is true?

They have the same acceleration

Ball A is thrown up and Ball B is thrown down, both with the same initial speed, and both at the same height. Neglecting air resistance, just prior to hitting the ground, which of the following is true?

They have the same speed

You drop a ball from a window on an upper floor of a building. It strikes the ground with speed v. You now repeat the drop, but you have a friend down on the street who throws another ball upward at speed v. Your friend throws the ball upward at exactly the same time that you drop yours from the window. At some location, the balls pass each other. Which of the following is true?

This location is above the halfway point between the window and the ground

An object falls freely from a height, H. It is released at t = 0 and strikes the ground at t = T. Consider the time at which the object is at a height of H/2. Also consider the height at which the object is located at the time T/2. Which of the following is true?

When the object is at a height H/2, the time is greater than T/2 and when the time is T/2, the object is at a height of more than H/2.

Let's say that during a thunderstorm you measure the time lag between the flash and the thunderclap to be 3 seconds. If the speed of sound is about 340 m/s, which of the following is the best estimate of your distance to the lightening bolt? about 3 km about 0.3 km about 1 km about 10 km

about 1km

A sailor drops a wrench from the top of a sailboat's mast while the boat is moving steadily and rapidly in a straight line. Where will the wrench hit the deck?

at the base of the mast

As a projectile thrown upward at a non-vertical angle moves in a parabolic path, as in the figure, at what point along its path are the velocity and acceleration vectors for the projectile perpendicular to each other?

at the highest point

The velocity and acceleration of an object...

can have opposite signs

The equations of kinematics, which are given in the table,....

cannot be used if the acceleration varies with time

The gravitational potential energy of a system

depends on the reference configuration for zero potential energy

A book is moved once around the perimeter of a tabletop with the dimensions 1.0 m × 2.0 m. If the book ends up at its original position, what is its displacement and what is the distance it traveled?

displacement of 0 m, distance traveled 6 m

A dart is loaded into a spring-loaded toy dart gun by pushing the spring in by a distance d. For the next loading, the spring is compressed a distance d/2. How much faster does the second dart leave the gun compared with the first?

half as fast

A block of mass m is resting on a ramp making an angle θ with respect to the horizontal. The coefficient of static friction and the coefficient of kinetic friction for this surface are ms and mk, respectively. If the block does not slide, then the frictional force holding the block must be

mg sin θ

As a projectile thrown upward at a non-vertical angle moves in a parabolic path, at what point along its path are the velocity and acceleration vectors for the projectile parallel to each other?

nowhere

If A → + B → = 0 , the corresponding components of the two vectors A → and B → must be

of opposite sign

A dart is loaded into a spring-loaded toy dart gun by pushing the spring in by a distance d. For the next loading, the spring is compressed a distance d/2. How much work is required to load the second dart compared to that required to load the first?

one-fourth as much

When you draw the free-body diagram for a single object, you must sketch

only the forces that act on the object

In a machine shop, two cams are produced, one of aluminum and the other of cast iron. Both cams have the same mass. Which cam is larger?

the aluminum cam

In the case of a force varying with position, what feature of the graph of force vs. position represents the work done during a displacement?

the area under the curve

When you sit in a chair there is necessarily a reaction force to the gravitational force acting on your body. Which of the following best describes this reaction force?

the force of gravity you exert on the Earth

A race car moving quickly around a track collides with a mosquito, which splatters on the car's windshield. Which object experiences a greater magnitude acceleration?

the mosquito

Which of the following is (are) conserved in an isolated system?

the sum of the kinetic energy and the potential energy

Which of the following would serve as the best time standard?

the vibration of a CS- 133 atom

Two cars, A and B, are moving with constant velocities, v → A L and v → B L, across a vacant parking lot, the velocities given with respect to the lot thus explaining the L in the subscripts. What is the relative velocity, v → A B , of car A as seen from car B?

v → A L − v → B L

Taking up as positive, which values represent the ball's vertical velocity and acceleration at points A, C, and E in the figure?

vy = 0; ay = -9.8 m/s2

If a car is traveling eastward and slowing down, what is the direction of the acceleration on the car that causes it to slow down?

westward

You place a box on a smooth and evenly-sanded wooden board. Raise one end of the board so that the angle increases. Eventually, the box starts to slide along the board. If you maintain this angle of the board, the box

will speed up along the ramp

The gravitational force exerted by the Earth on the Moon holds the moon in an orbit around the Earth. Let us assume that the orbit is perfectly circular. The work done by this gravitational force during a one week interval in which the moon moves through a displacement in its orbital path is

zero