Physics 1st semester Exam
Angular velocity is defined as the rate at which A) the angle changes B) the linear speed changes C) inward change of distance D) inward gravitional force
A
Referring back to test #1, Fig 2-2, what is the acceleration in 1 sec.? A) 0 B) 10 m/s^2 C) 2 m/s^2 D) -2.5 m/s^2
B) 10 m/s^2
Of the following, which is not a unit of power? A) joule / second B) newton-meter / second C) watt / second D) watt
c
While you are riding in a car at 21.0 m/s, the light ahead turns red. The car decelerates at a constant rate in 6.0 s to a stop. What distance has the car traveled during the constant deceleration?
63 m
A 12 kg object is moving on a rough, level surface. It has 24 J of kinetic energy. The friction force on it is a constant .50 N. How far will it slide? A) 48 m B) 24 m C) 2.0 m D) 12 m
A
A ball of mass 0.10 kg is dropped from a height of 12 m. Its momentum when it strikes the ground is A) 1.5 kgxm/s B) 1.8 kgxm/s C) 4.8 kgxm/s D) 2.4 kgxm/s
A
A piece of wood is floating in a bathtub. The second piece of wood sits on top of the first piece and does not touch the water. If the top piece is taken off and placed into the water, what happens to the water level in the tub? A) it does not change B) it goes up C) it goes down D) cannot be determined
A
An arrow of mass 20 g is shot horizontally into a bale of hay, striking the hay with a velocity of 60 m/s. It penetrates a depth of 20 cm before stopping. What is the average stopping force acting on the arrow? A) 180 N B) 360 N C) 90 N D) 45 N
A
If you push a 4.0 kg mass with the same force you push a 10 kg mass from rest, A) the 4.0 kg accelerates 2.5 times faster than the 10 kg mass B) both masses accelerates at the same rate C) the 10 kg mass accelerates 2.5 times faster than the 4.0 kg mass D) none of the above is true
A
In the absence of an external force, a moving object will A) move with constant velocity B) slow down and eventually come to a stop C) stop immediately D) go faster and faster
A
Object A weighs 40 N on Earth, and object B weighs 40 N on the moon. The moon's gravity is one sixth of the Earth's. Compare the masses of the object. A) B has 6 times the mass of A B) A and B have equal masses C) A has 6 times the mass of B D) The situation as stated is impossible
A
Satellite A and Satellite B have the same mass. Satellite A orbits the Earth at an altitude of 300 km and Satellite B orbits Earth at an altitude of 400 km. Which of the following is true concerning their orbital velocity? A) Sat. A is traveling faster than B B) B is traveling faster than A C) A is traveling at the same speed as B D) There is not enough info
A
Starting from rest, a 4.0 kg body reaches a speed of 8.0 m/s in 2.0 s. What is the net force acting on the body? A) 16 N B) 4.0 N C) 8.0 N D) 32 N
A
The kinetic friction force between a 60.0 kg object and a horizontal surface is 50.0 N. If the initial speed of the object is 25.0 m/s, what distance will it slide before coming to a stop? A) 375 m B) 250 m C) 30.0 m D) 15.0 m
A
Two boxes of masses m and 2m are in contact with each other on a frictionless surface. ( See Fig. 4-3 on test 2) What is the acceleration of the more massive box? A) F / (3m) B) F/ (4m) C) F / m D) F / (2m)
A
Two planets have the same surface gravity but planet B has twice the mass of planet A. If planet A has a radius of r, what is the radius of planet B? A) 1.41 r B) 0.707 r C) r D) 4r
A
What is the angular velocity of a 0.500 m diameter tire when the car travels at 22.0 m/s? A) 88 rad/s B) 22 rad/s C) 0.14 rad/s D) 35 rad/s
A
When you blow air above a paper strip, the paper rises. This is because A) the aire above the paper moves faster and the pressure is lower B) the air above the paper moves faster and the pressure is higher C) the air above the paper moves slower and the pressure is lower D) the air above the paper moves slower and the pressure is higher
A
In the picture, what is the velocity at t=4.0 s? A) 0 B) -40 m/s C) 10 m/s D) 20 m/s
A) 0... because the graph plateaus off
An object is moving in a straight line with constant acceleration. Initially, it is traveling at 16m/s. Three seconds later it is traveling at 10 m/s. How far does it move during this time? A) 39m B) 48m C) 57m D) 30m
A) 39m... because 10=16+3a -6=3a -2=a x=(16)(3) + .5(-2)(3)^2 39m
Two vectors, of magnitudes 20 and 50, are added. Which one of the following is a possible answer for the magnitude of the resultant? A) 40 B) 10 C) 80 D) 20
A) 40... because 30-70
50 cm^3 of wood is floating on water, and 50cm ^3 of iron is totally submerged. Which has the greater bouyant force? A) wood B) iron C) both have the same D) cannot be determined
B
A 4.0 N force acts for 3.0s on an object. The force suddenly increases to 15 N and acts for one more seconds. What imoulse was imparted by these forces to the object? A) 12 Nxs B) 27 Nxs C) 15 Nxs D) 19 Nxs
B
A constant net force acts on an object. Describe the motion of the object. A) constant speed B) constant acceleration C) increasing acceleration D) constant velocity
B
A person on a scale rides in an elevator. If the mass of the person is 60.0 kg and the elevator accelerates downward with an acceleration of 4.90 m/s^2, what is the reading on this scale? A) 588 N B) 294 N C) 147 N D) 882 N
B
A roller coaster starts from rest at a point 45 m above the bottom of a dip (Fig. 6-2 of test 4). Neglect friction, what will be the speed of the roller coaster at the top of the next slope, which is 30 m above the bottom of the dip? A) 14 m/s B) 17 m/s C) 30 m/s D) 24 m/s
B
An object floats with half its volume beneath the surface of the water. The weight of the displaced water is 2000 N. What is the weight of the object? A) 4000 N B) 2000 N C) 1000 N D) cannot be determined
B
How does the centripetal acceleration change for an object that maintains the same speed but the radius of the curved path is reduced to half? A) quadruples B) doubles C) halved D) quatered
B
Pressure is A) inversely proportional to force and proportional to area. B) proportional to force and inversely proportional to area. C) inversely proportional to both force and area D) proportional to both force and area
B
Satellite A has twice the mass as Satellite B and it revolves the same orbit above Earth. Compare the speeds of the satellites. A) The speed if B is half the speed of A B) The speed of B is equal to the speed of A C) The speed of B is one fourth the speed of A D) The speed of B is twice the speed of A
B
Two objects with masses m and n are originally a distance of r apart. The magnitude of the gravitational force between them is F. If each mass is doubled and the radius is quadrupled, what is the magnitude of the new gravitational force? A) 4 F B) F/4 C) 16F D) F/16
B
Two toy cars (16 kg and 2 kg) are released simultaneously on an inclined plane that makes an angle of 30 degrees with the horizontal. Make a statement which best describes their acceleration after being released. A) The 16 kg car accelerates 8 times faster than the 2 kg car B) Both cars accelerate at the same rate C) The 2 kg car accelerates 8 times faster than the 16 kg car D) none of the above
B
What is the gauge pressure at location 15 m below the surface of the sea? (The density of seawater is 1.03x 10^3 kg/m^3) A) 2.52 x 10^5 N/m^2 B) 1.51 x 10^5 N/m^2 C) 1.01 x 10^5 N/m^2 D) 1.47 x 10^5 N/m^2
B
What is the tangential velocity of a child 3.0 m from the center of a merry-go-round with an angular velocity of 0.400 rad/s? A) 0.13 m/s B) 1.2 m/s C) 7.5 m/s D) 47 m/s
B
Which of the following is associated with the law of conservation? A) Pascal's principle B) Bernoulli's principle C) equation of continutiy D) Archimedes' principle
B
A cart with an initial velocity of 5.0 m/ experiences a constant acceleration of 2.0 m/s^2. What is the cart's displacement during the first 6.0 s of its motion? A) 55m B) 66m C) 10m D) 80m
B) 66m... because displacement(X)= 5x6+.5(2)(6)^2
If you are driving 72 km/h along a straight road and you look to the side for 4.0s, how far do you travel during this inattentive period? A) 40m B) 80m C) 20m D) 18m
B) 80m... because 4x20=w/4 x 4
When an object is released from rest and falls in the absence of friction, which of following is true concerning its motion? A) Its velocity is constant. B) Its acceleration is constant. C) Neither its acceleration nor its velocity is constant. D) Both its acceleration and its velocity are constant.
B) Its acceleration is constant.
A 1.0 m^3 object floats in water with 20 % of it above the waterline. What does the object weigh out of the water? A) 1960 N B) 11800 N C) 7840 N D) 9800 N
C
A 2.0 kg mass moves with a speed of 5.0 m/s. It collides head-on with a 3.0 kg mass at rest. If the collision is perfectly inelastic, what is the speed of the masses after the collision? A) 10 m/s B) 0, since the collision is inelastic C) 2.0 m/s D) 2.5 m/s
C
A 30.0 N stone is dropped from a height of 10.0 m, and it strikes the ground with a velocity of 7.00 m/s. What average force of air friction acts on it as it falls? A) 293 N B) 225 N C) 22.5 N D) 75.0 N
C
A solid object floats in water with 3/4 of its volume beneath the surface. What is the object's density? A) 1333 kg/m^3 B) 250 kg/m^3 C) 750 kg/m^3 D) 1000 kg.m^3
C
An ideal fluid flows at 12 m/s in a horizontal pipe. If the pipe widens to twice its original radius, what is the flow speed in the wider section? A) 12 m/s B) 4 m/s C) 3 m/s D) 6 m/s
C
As the speed of a moving fluid increases, the pressure in the fluid A) is constant B) increases C) decreases D) may increase or decrease
C
Mass and weight A) are both measured in kilograms B) are exactly equal C) are two different quantities D) both measure the same thing
C
Salt water has a greater density than fresh water. A boat floats in both freshwater and in salt water. Where is buoyant force greater on the boat? A) Salt Water B) Fresh C) Same in both D) Impossible to determine
C
The mass of mercury is 3.285x10^23 kg and its mean radius is 2440 km. What is the acceleration due to gravity at the surface? A) 2.94 m/s^2 B) 3.19 m/s^2 C) 3.68 m/s^2 D) 4.19 m/s^2
C
What force should be exerted down on a lever 3.0 m from the fulcrum to lift 100.0 kg placed 1.20 meters from the fulcrum on the other side? A) 250 N B) 360 N C) 392 N D) 2940 N
C
Which of the following is not a unit of pressure? A) Pascal B) mm of mercury C) n/m D) atmosphere
C
Objects A and B both start from rest. They both accelerate at the same rate. However, object A accelerates for twice the time as object B. What is the distance traveled by object A compared to that of object B? A) the same distance B) twice as far C) four times as far D) three times as far
C) four times as fast
A 16.0 kg mass is taken from Earth to the moon where gravity is one-sixth. Which of the following is true? A) The mass and weight are greater B) The mass and weight are less C) The mass is greater but the weight is less D) None are correct
D
A car is negotiating a flat curve radius of 50 m with a speed of 20.0 m/s. The centripetal force provided by friction is 1.2x10^4 N. What is the mass of the car? A) 500 kg B) 1000 kg C) 2000 kg D) 1500 kg
D
A curve of radius 80.0 m is banked at 45.0 degrees (make sure calc is in degreee mode). Suppose an ice storm reduces the friction to nearly zero. What is the safe speed necessary to rund the curve? A) 392 m/s B) 9.40nm/s C) 12.7 m/s D) 19.8 m/s
D
A spring-driven dart gun propels a 10-g dart. It is cocked by exerting a force of 20 N over a distance of 5.0 cm. With what speed will the dart leave the gun, assuming the spring has negligible mass? A) 17 m/s B) 10 m/s C) 20 m/s D) 14 m/s
D
An object moves with a constant speed of 30.0 m/s on a circular track of radius 150 m. What is the acceleration of the object? A) 0.17 m/s^2 B) 5.0 m/s^2 C) zero D) 6.0 m/s^2
D
Consider three drinking glasses. All three have the same area base, and all three and filled to the same depth with water. Glass A is cylindrical. Glass B is wider at the top than at the bottom, and so holds more water than A. Glass C is narrower at the top than the bottom, and so hold less water than A. Which glass has the greatest liquid pressure at the bottom? A) A B) B C) C D) all three have equal pressure
D
If the network done on an object is negative, then the object's kinetic energy A) increases B) is zero C) remains the same D) decreases
D
If you push twice as hard against a stationary brick wall, the amount of work you do A) is cut in half B) remains constant but non-zero C) doubles D) remains constant at zero
D
Liquid flows through a 4.0 cm diameter pipe at 1.0 m/s. There is a 2.0 cm diameter restriction in the line. What is the velocity in this restriction? A) .5 m/s B) 2 m/s C) .25 m/s D) 4 m/s
D
Matthew pulls his little sister Sarah in a sled on an icy surface (assume no friction), with a force of 60.0 N at an angle of 37 degrees upward from the horizontal. If he pulls her a distance of 12.0 m, what is the work done by Matthew? A) 720 J B) 185 J C) 433 J D) 575 J
D
On test 2, fig. 4-2, if the tensions in the ropes are 50 N, what is the mass of the traffic light? A) 8.1 kg B) 4.1 kg C) 3.1 kg D) 6.1 kg
D
The gravitational force between the two masses is F. The masses are moved one-third to their original distance, what is the gravitational attractive force? A) 3 F B) F/3 C) F/9 D) 9F
D
An object is thrown upward with a speed of 12 m/s on the surface of planet X where the acceleration due to gravity is 1.5 m/s^2. How long does it take for the object to reach the max height? A) 14s B) 16s C) 11s D) 8.0s
D) 8.0s... because 0=12+1.5t t=8
While performing a lab where you measure the weight of an unknown block to be 1.75 N. The mass is now submerged in water and the tension in the string suspending the block is 1.48 N. a) What is the buoyant force on the block? b) What is the volume of the displaced fluid? c)What is the density of the block?
a) .027 N b) 2.76 x 10^-6 c) 64935.06 kg/m^3
A circular PVC tube has a diameter of 18 sm at point A as it transports water from a reservior containing 2500 L. The tube narrows to a diameter of 12 cm at point B. The water at point B is measured to be flowing at 3.5 m/s. a) What is the flow rate in m^3/s? b) What is the speed of the fluid at point A? c) Where is the pressure greater on the walls of the pipe (A or B)?
a) .0395 m^3/s b) 1.56 m/s c) A
Franklin stands atop a bridge with water flowing 8.00 meters below. He drops a rock and it splashes into the water below. a) How long does it take to strike the water? He throws a stone up and the rock splashes in the water after 3.10. b) How fast did Franklin throw the rock?
a) 1.27 s b) 12.6 m/s
A 650.0 g ball is connected to a 72.0 cm string swung in a vertical circle at 42.0 rpms. a) What is the period of time for one revolution? b) What is the tension in the string at the lowest period? c) What is the mininmum speed necessary to keep the ball in uniform circular motion?
a) 1.43s b) 15.4 N c) 2.66 m/s^2
At the top of a snowy hill, you start your descent from rest upon your trusty sled. After the 3.60 seconds, your sled has gone 12.0m down the hill. a) What is the average acceleration of you and your sled down the hill? b) What is your velocity after 5.0 seconds of this constant acceleration?
a) 1.852 s b) 9.26 m/s
A slingshot launches a pebble with a speed of 28.0 m/s 30 degrees above the horizontal. If the pebble lands at the same height it was launched, a) How long was it in the air? b) How far did it travel horizontally? c) What was the max height achieved relative to where it was launched?
a) 2.9 s b) 70.18 m c) 10 m
A tennis ball is thrown horizontally from a window striking the pavement below 2.20 seconds later. The ball hits the pavement 37.5 m from the base of the building. a) How high is the window above the pavement? b) With what speed was the tennis ball thrown?
a) 23.7 m b) 17 m/s
Mars: 6.42x10^23 kg (mass) ; 687 Earth days (period); 3.40x10^6 m(radius) Neptune: 1.02x10^26 (mass) ; 59800 Earth days (period) ; 2.46x10^7 m (radius) a) How fast would a satellite have to be traveling to maintain an orbit around Mars at an altitude of 1400 km? b)How long would it take to orbit Mars one time?
a) 2986.8 m/s b) 10097 s
Mars: 6.42x10^23 kg (mass) ; 687 Earth days (period); 3.40x10^6 m(radius) Neptune: 1.02x10^26 (mass) ; 59800 Earth days (period) ; 2.46x10^7 m (radius) a) What is the gravitational acceleration at the surface of Mars? b) What is the gravitational acceleration at the surface of Neptune? c) Which planet has a greater orbital velocity around the Sun?
a) 3.7 m/s^2 b) 11.24 m/s^2 c) Mars
A ball is thrown downward from the top of building with an initial speed of 25 m/s. It strikes the ground after 2.0 s. How high is the building? A) 70m B) 30m C) 20m D) 50m
a) 70
An object floating in water with 18% of its volume above the water. The same object is now placed in an unknown fluid but is observed to float with 12 % of its volume out of the fluid. a) what is the density of the object? b) what is the specific gravity of the unknown fluid?
a) 820 kg/m^3 b) .932 SG
A hydraulic lift is used to lift a 1500 kg car on a platform measuring 2.4 m^2. a) what force is applied to the other end where the area is a square measuring 8 cm x 8 cm? b) how would the force apply to lift the same car change if the area were reduced to a 4 x 4 sm area?
a) F= 39.2 N b) F = 9.8 N, so it is 1/4 of the F from before
An 890 kg sports car collides into the back of a 1500 kg truck stopped at a light. The dry road conditions indicate a coefficient of kinetic friction of 0.35. The two vehicles slide together 2.5 meters after impact. a) What was the force of friction of the car and truck combined? b) What was the velocity of the car and truck immediately after impact? c) What was the initial speed of the sports car?
a) F= 8197.7 N b) v= 4.141 m/s c)Va= 11.120 m/s
A soccer ball is kicked toward a fence 2.50 meters tall and is 32.0 meters away. The ball leaves the player's foot with a speed of 20.0 m/s and at an angle of 37 degrees above the horizontal. a) Determine the velocities in the x and y directions. b) How long does it take the ball to reach the plane of the fence? c) Does the ball clear the fence? If so by how much, or if not, by how much?
a) Vx= 16 m/s and Vy= 12 m/s b) 2s c) Yes, by 1.9m
A sled is at the top of a 3.0 m long incline at 37 degrees with the horizontal (test 4, free response #1). The coefficient of friction is 0.25. a) What will be the speed of the sled at the bottom of the incline? b) How far will the sled slide horizontally assuming the coefficient remains constant?
a) v= 4.863 m/s b) d= 4.8 m
A 0.005 kg bullet is at the end of a spring with a constant of 1950 N/m which is compressed 12.0 cm. a) When the spring is released, what will be the speed of the bullet? b) The bullet then embeds itself into a block of wood with a mass of 0.090 kg, what is the speed of the block and bullet after the collision? c) If the block is initially suspended from a 3.0 m long string, what will be the max angle the string makes with the vertical?
a) v= 74.94 m/s b) vb= 3.94 m/s c) theta= around 43 degrees
Car J moves twice as fast as car K, and car J has half the mass of K. The kinetic energy of car J, compared to car K is A) 4 to 1 B) 2 to 1 C) the same D) 1 to 2
b
The mass of 0.45 kg is connected to one end of a string and the other end of the string is connected to a 0.38 kg mass. The string passes over a pulley of negligible friction. a) label the free body diagram. b) What is the acceleration of the system? c) Determine the tension in the string. d) If each mass were increased but the difference of mass between them remained the same, would the acceleration increase, decrease, or remain the same?
b) .827 m/s^2 c) 4.083 N d) decrease
A 3.7 kg black starts at rest on the table and the coefficient of friction is 0.35. The block is attached to a string which goes over a pulley and a 2.0 kg mass hangs vertically. a) label the free body diagram. b) What is the force of friction? c) What is the acceleration of the system? d) What is the tension in the string during the acceleration?
b) 12.691 N c) 1.21 m/s^2 d) 17.18 N
A block of mass "m" is on a 32 degrees incline. a) label the forces b) What would be the acceleration of the block if the coefficient of kinetic friction is 0.20? c) What would be the acceleration if the coefficient of friction were doubled?
b) 3.5 m/s^2 c) 1.9 m/s ^2
A mass starts at rest atop a 3.0 m ramp as shown below (question 4 of free response to test 2). The ramp incline is 37 degrees and the coefficient of friction is 0.25. a) label the free body diagram. b) What is the acceleration of the block down the incline? c) How long does it take the block to slide down the ramp?
b) 3.64 m/s^2 c) 1.23 s
A force F accelerates the 85 kg crate horizontally across a rough floor at 1.4 m/s^2. The coefficient of friction is 0.60. Using the picture below, a) label the free body diagram. b) determine the force of friction, c) What is the force F?
b) F = 499.8 N c) F = 620 N
Compared to yesterday, you did 3 times the work in one-third the time. To do so, your power output must have been A) the same as yesterday's B) 3 times yesterday's C) 9 times yesterday's D) one-third yesterday's
c