physics tests
When a car makes a sharp left turn, what causes the passengers to move toward the right side of the car?
inertia
Which one of the following terms is used to indicate the natural tendency of an object to remain at rest or in motion at a constant speed in a straight line?
inertia
Suppose you are given a position versus time graph. The slope of a line drawn tangent to a point on the curve of this graph describes what quantity?
instantaneous velocity
When an object is moving with uniform circular motion, the object's tangential speed
is constant
The graph above describes the motion of a cyclist. The graph illustrates that the acceleration of the cyclist
is constant.
When an object is moving with uniform circular motion, the centripetal acceleration of the object
is directed toward the center of motion.
The length of the force vector is proportional to what property of a force?
magnitude
In the graph above, what is the correct description of any location to the left of the zero?
negative position
An astronaut is standing on the edge of a cliff on Mars. The astronaut throws a wrench upward, and it lands at the base of the cliff below. For each pair of terms below: if the first term is increased, tell whether the effect on the second term will be to increase it, decrease it or it stays the same:Mass of the wrench / time in flight
no affect on time in flight
A ball is in free fall.
nonequilibriam
A car speeds up.
nonequilibriam
The normal force is always
perpendicular to the surface.
A 1.7 kg ball is whirled on a 1.4 m string so that the ball moves in uniform circular motion in a horizontal plane. The tension in the string is 33 N, and the string is at a 31° angle below the horizontal plane, (a conical pendulum).a. Make a free body diagram of the ball. b. What is the radius of the horizontal circle? c. What is the tangential speed of the ball?
B. 1.2 M C. 4.468 m/s
If ball A was launched horizontally at a height of 1m and ball B was launched horizontally at a height of 3 m at the same velocity as A then which ball would hit the ground first?
Ball A
If ball A was launched horizontally at a height of 1m and ball B was launched at a height of 3 m at the same velocity as A then which ball would have the greater range?
Ball B
According to the graph above, during which interval does the cat have the greatest positive velocity?
0.0-5.0 s phone pic
An ice skater moving at 10.0 m/s coasts to a halt in 100 m on a smooth ice surface. What is the coefficient of friction between the ice and the skates?
0.051
A car with a speed of 13.7 m/s enters a curve of radius 60 meters. At this speed, the car barely maintains traction with the road. The road is horizontal, and is not banked.Calculate the coefficient of friction between the car and the road. Answer to 2 places past the decimal.
0.32
A projectile launched horizontally hits the ground in 0.5 seconds. If it had been launched with a much higher speed in the same direction, it would have hit the ground in ________.
0.5 s
A 194.7 N crate rests stationary on a 34° ramp. What is the coefficient of static friction? Answer to 3 places past the decimal. (Note: If your last digit is zero and the software wont accept it or drops it, just leave it that way.)
0.675
A child rides a bicycle in a circular path with a radius of 9.8 m. The tangential speed of the bicycle is 4.2 m/s. The combined mass of the bicycle and the child is 43 kg.What is the magnitude of the bicycle's centripetal acceleration? Answer to 2 places past the decimal.
1.8
A child pulls a wagon with a force directed 42.0o above the horizontal. If the vertical component of the force on the wagon is 86.8 N, what is the force exerted on the handle? Answer to 1 place past the decimal. (Note: If your last digit is zero and the software wont accept it or drops it, just leave it that way.)
129.7
A child rides a bicycle in a circular path with a radius of 19.2 m. The tangential speed of the bicycle is 8 m/s. The combined mass of the bicycle and the child is 43 kg.What is the magnitude of the centripetal force on the bicycle? Answer to 1 place past the decimal.
143.3
Consider the figure above. M1 = 76,550 kg, M2 = 65,418 kg, and M3 = 42,141 kg.d1 = 0.05 meters, and d2 = 0.075 meters.Find the net force on M1. Answer in magnitude only to 2 places past the decimal.
147.38
Stephen Seagal has gone to the Arctic Ocean to hunt baby seals. Mr. Seagal is on a 3.5 meter high chunk of sea ice when he sees a seal in the ocean. He jumps horizontally off the ice at 18.7 m/s. How far away does he jump? Answer to one place past the decimal.
15.8
An airplane with a mass of 1.20 ´ 104 kg tows a glider with a mass of 0.60 ´ 104 kg. If the airplane propellers provide a net forward thrust of 3.60 ´ 104 N, what is the acceleration of the glider? (Disregard friction.)
2.00 m/s2
A 703.1 kg crate slides down a frictionless ramp at an angle of 18.4º. Find the crate's acceleration. Answer to 2 places past the decimal.
3.1
In the free-body diagram shown above, which of the following is the gravitational force acting on the balloon?
4050 N
In the absence of air resistance, the angle at which a thrown ball will go the farthest is __________.
45°
A coin released from the top of a tower hits the ground after falling 148 m. How long before the coin hits the ground? Answer to two places past the decimal.
5.49
A ball is attached to a string, and is being swung in a vertical circle: A student swings a 1.0 kg ball in a vertical circle with radius 1.25 meters. The student finds that it takes 8.30 seconds for the ball to complete 10 revolutions.Calculate the tension in the string at the top of the circle. Answer to one place past the decimal.
61.8
What is the minimum unknown mass needed to maintain static equilibrium if the coefficient of friction is 0.37 for both surfaces?
9.397kg
A sled weighing 1.0 ´ 10 N is held in place on a frictionless 20.0° slope by a rope attached to a stake at the top. The rope is parallel to the slope. What is the normal force of the slope acting on the sled?
94 N
Which of the following situations represents a negative displacement?
A cat jumps from a tree limb to the ground.
Consider a box, M1, attached by a massless string over a frictionless pulley to a hanging object, M2. The box, M1, has a mass of 100 kg, while the hanging object, M2, has a mass of 200 kg. The ramp has a coefficient of friction of 0.20 .a. Find the acceleration of the box b. Find the tension in the string.
A. 5.886 m/s^2 B. 784.8N
Consider the projectile path in Figure 1. Which point has the maximum horizontal velocity?
All have the same value
Consider two objects, M1 and M2, that attract each other with Force, "F", when they are separated by distance "d". If the mass on each object reduced to one-fourth of the original value, and the distance between them is reduced to 1/2 of the original value, then the new force of gravitational attraction becomes:
F/4
Horizontal acceleration varies with displacement.
False
Horizontal velocity is zero at the top of the trajectory
False
The projectile's total time in flight is 2 x the upward flight time
False
Which pair of graphs below represent the same motion of an object?
Graph Pair A check phone pic
Which of the following statements applies to the motion of a ball rising and then falling in free fall?I. The ball has constant acceleration as it moves upward.II. The ball has constant acceleration at the top of its path.III. The ball has constant acceleration as it moves downward.
I, II, and III
Two objects, A and B, accelerate from rest with the same constant acceleration. However, object A accelerates for twice as much time as object B.Which of the following statements must be true about the objects at the end of their respective periods of acceleration?
Object A will travel twice as far as object B
Consider the cart on a track below as the initial condition. A force is applied acting to the right. Assume that friction is negligible. The towing force is applied at an angle as in the picture below, what effect will this change have on the acceleration of the object?
The acceleration of the new condition will be less than the initial condition.
Consider the cart on a track below as the initial condition. A force is applied acting to the right. Assume that friction is negligible. If the 0.5 N is applied to two 500 g carts hooked together, what effect will this change have on the acceleration of the object?
The acceleration remains the same.
In the graph above, how does the acceleration at A compare with the acceleration at B?
The accelerations at A and B are each zero. phone pic
When a car's velocity is negative and its acceleration is negative, what is happening to the car's motion?
The car speeds up.
What are the units of the coefficient of friction?
The coefficient of friction has no units.
A leaf falls from a tree and lands on the sidewalk. Identify an action-reaction pair in this situation.
The leaf exerts a force on the sidewalk; the sidewalk exerts a force on the leaf.
You and a friend go to Cape Canaveral, Florida to watch a rocket launch. How can you explain to your friend the physics of a rocket launch?
The rocket applies a force to the fuel, and the fuel applies a force to the rocket
A stone is tied to a string and whirled in a vertical circle at some radius. Which of the following CANNOT be true? SELECT TWO ANSWERS.
The tension force is the same everywhere in the circle; The tension force and the weight of the stone always affect the centripetal force.
A cannonball is shot horizontally, in a northward direction, at 50 m/s. Which graph below best illustrates the vertical velocity?
Time arrow going right, with v line under it going down right straight
Vertical velocity is zero at the top of the trajectory
True
An automobile moves at constant speed down one hill and up another hill along the smoothly curved surface shown above. Which of the following diagrams best represents the directions of the velocity and the acceleration of the automobile at the instant that it is at the highest position as shown?
V arrow -> a arrow down;; image is a car on a hill
The diagram above represents the path of a stunt car that is driven off a cliff, (neglecting air resistance).How does the magnitude of the vertical component of velocity of the car at point A compare to the vertical component of the velocity of the car at point B?
Velocity A < Velocity B
The diagram above represents the path of a stunt car that is driven off a cliff, (neglecting air resistance).How does the magnitude of the horizontal component of the car's velocity at point A compare with the horizontal component of velocity at point B?
Velocity A = Velocity B
Is it possible for an object moving with a constant speed to accelerate? Explain.
Yes, although the speed is constant, the direction of the velocity can be changing.
Consider the figure above. The Applied Force is 47 Newtons, and has an angle of 35º. The box has a mass of 6.75 kilograms, and the coefficient of friction is 0.21.a. Find the acceleration of the box b. If the box starts from rest, find the displacement after 5.0 seconds.
Your Answer: A. 2.805 m/s^2 B. 35.062m
You are pushing a heavy crate and it doesn't move. What must be true?
Your FA is less than or equal to the maximum Ff.
Which of the following line segments on a position versus time graph is physically impossible?
a vertical line
Which of the following can be a centripetal force?
all of the above; gravity, friction, tension
If you know the acceleration of a car, its initial velocity, and the time interval, which of the following can you predict?
all of the above; the direction of the car's final velocity the magnitude of the car's final velocity the displacement of the car
Four arrows are shot horizontally from the top of a tower, as shown below. Which arrow will hit the ground first?
all will hit at the same time
Three strings, as shown above, suspend a fish of mass 4.5 kg. If T2 is 83.3 N, Find the angle and T1.
angle= 32 degrees T1= 70.643N
A baseball catcher throws a ball vertically upward and catches it in the same spot as it returns to the mitt. At what point in the ball's path does it experience zero velocity and nonzero acceleration at the same time?
at the top of its path
Two objects a constant distance apart, have masses m1 and m2. If the product of the masses is increased by a factor of three, then the gravitational force between the objects will
be 3x larger
Which of the following would occur if a 500 gram solid ball and a 1,000 gram solid ball are dropped in a vacuum from the same height above the ground?
both balls will hit the ground at the same time
A car moves at a constant velocity.
dynamic equilibrium
An action exerted on an object which may change the object's state of rest or motion defines
force
A child rides a bicycle in a circular path with a radius of 2.0 m. The tangential speed of the bicycle is 2.0 m/s. The combined mass of the bicycle and the child is 43 kg.What kind of force provides the centripetal force on the bicycle?
friction
As a basketball player starts to jump for a rebound, the player begins to move upward faster and faster until his shoes leave the floor. At the moment the player begins to jump, the force of the floor on the shoes is
greater than the player's weight.
In what direction does the force of air resistance act?
in the opposite direction of the falling object
The centripetal force on an object in circular motion is
in the plane of the object's motion and pointed inward toward the center.
An object is launched at some angle. Indicate how changing the first value will affect the second value, (if all other values stay the same) If the launch angle is increased from 10° to 40°, the range, (x), will increase If the launch angle is increased from 50° to 80°, the range, (x) will decrease If the launch angle is increased from 10° to 40°, the maximum height, (y) will Increase If the launch angle is increased from 50° to 80°, the maximum height, (y), will increase
increase, decrease, increase, increase
A car is stationary in a flat parking lot.
static equilibriam
A cat sleeps on an inclined surface.
static equilibriam
How does the coefficient of static friction for two surfaces in contact compare to the coefficient of kinetic friction for the same two surfaces?
static is more than kinetic
Consider the car below, driving on a horizontal roadway; In the free-body diagram shown above, the 5800 N force represents the
the Frictional Force felt by the car
The earth revolves around the sun in circular motion. The earth is experiencing a constant centripetal acceleration. The existance of this centripetal acceleration indicates that:
the earth's direction of motion is constantly changing
Which force is responsible for holding a car on the road while driving on an unbanked curve?
the force of friction
The horizontal component of a projectile's velocity is a function of
the launch velocity
Complete the following statement: "The term 'Net Force' most accurately describes ..."
the quantity that causes an object to accelerate
A ball is thrown upwards, reaches its highest point, and then falls back to its starting point. Which graph best illustrates the velocity of the ball?
the time "line" is in the middle, the v line starts from top of the graph and goes down right through the time line
An object moves in a circular path at a constant speed. Compare the direction of the object's velocity and centripetal force vectors.
the two vectors are perpendicular
Two students are standing on the edge of a 15 meter tall cliff. Hoss throws a golf ball horizontally at 15 m/s. At exactly the same time, Blossom throws a shot put horizontally at 25 m/s. Which of the two projectiles will hit the ground first?
they will hit at the same time
A cannonball is shot horizontally, in a northward direction, at 50 m/s. Which graph below best illustrates its horizontal velocity?
time arrow going right, under the V line
The magnitude of the gravitational force acting on an object is
weight
In 1969, Neil Armstrong and 'Buzz' Aldrin landed on the moon. Because of the moon's smaller mass, its acceleration of gravity, "g", is 1/6 that of earth. Suppose the astronaut and pressure suit has a total weight on earth of 1962 N. How would this compare to the total weight on the moon?
weight on moon is less, (but not zero)
A car goes forward along a level road at constant velocity. The additional force needed to bring the car into equilibrium is
zero.
