Physics Test 2 Misconception Q's (Ch 4 & 5), Physics Test 3 Misconceptual Questions, Misconception Q's Test 4
The figure shows a 100 kg block being released from rest from a height of 1 m. It then takes 0.53 s for it to reach the floor. What is the mass m of the block on the left? There is no friction or mass in the pulley, and the connecting rope is very light a) 13 kg b) 14 kg c) 16 kg d) 11 kg
c
A stone is held at a height h above the ground. A second stone with four times the mass of the first one is held at the same height. The gravitational potential energy of the second stone compared to that of the first stone is a) 1/4 as much b) 1/2 as much c) twice as much d) 4 times as much e) the same
d
When a skier skis down a hill, the normal force exerted on the skier by the hill is: (a) equal to the weight of the skier (b) greater than the weight of the skier (c) less than the weight of the skier
c
When the speed of your car is doubled, by what factor does its kinetic energy increase? (a) the sq root of 2 (b) 2 (c) 4 (d) 8
c
Person X pushes twice as hard against a stationary brick wall as person Y. Which one of the following statements is correct? a) both do positive work, but person X does 4 times the work of Y b) both do positive work, but person X does twice the work of Y c) both do the same amount of positive work d) both do zero work e) both do positive work, but person X does 1/2 the work of Y
d
The moon does not crash into the Earth because: (a) the net force on it is zero (b) it is beyond the main pull of the Earth's gravity (c) it is being pulled by the Sun as well as by the Earth (d) it is freely falling but it has a high tangential velocity
d
A 25 kg piece of equipment can be hung by steel wires of length 1 m, 2 m, or 3 m. If all the wires have the same diameter, which one will stretch the greatest distance?
3 m
Which one has larger kinetic energy: a 500-kg object moving at 40 m/s or a 1000-kg object moving at 20 m/s?
500kg
A golf ball and an equal-mass bean bag are dropped from the same height and hit the ground. The bean bag stays on the ground while the golf ball rebounds. Which experiences the greater impulse from the ground? (a) the golf ball (b) the bean bag (c) both the same (d) not enough information
a
A truck has four times the mass of a car and is moving with twice the speed of the car. If Kt and Kc refer to the kinetic energies of truck and car respectively, it is correct to say that a) Kt = 16 Kc b) Kt = 4Kc c) Kt = 2Kc d) Kt = Kc e) Kt = 1/2 Kc
a
A truck is traveling horizontally to the right. When the truck starts to slow down, the crate on the (frictionless) truck bed starts to slide. In which direction could the net force be on the crate? (a) No direction. The net force is zero. (b) Straight down (because of gravity) (c) Straight up (the normal force) (d) Horizontal and to the right. (e) Horizontal and to the left.
a
A uniform beam is hinged at one end and held in a horizontal position by a cable. The tension in the cable: a) must be at least half the weight of the beam, no matter what the angle of the cable b) could be less than half the beam's weight for some angles c) will be half the beam's weight for all angles d) will equal the beam's weight for all angles
a
An astronaut is a short distance away from her space station without a tether rope. She has a large wrench. What should she do with the wrench to move toward the space station? (a) throw it directly away from the space station (b) throw it directly toward the space station (c) throw it toward the station without letting go of it (d) throw it parallel to the direction of the station's orbit (e) throw it opposite to the direction of the station's orbit
a
How much work would a child do while pulling a 12-kg wagon a distance of 4.3 m with a 22 N force? a) 95 J b) 52 J c) 67 J d) 109 J
a
Joe and Bill throw identical balls vertically upward. Joe throws his ball with an initial speed twice as high as Bill. If there is no air resistance, the maximum height of Joe's ball will be a) four times that of Bill's ball b) two times that of Bill's ball c) equal to that of Bill's ball d) eight times that of Bill's ball e) roughly 1.4 times that of Bill's ball
a
The figure shows a block of mass m resting on a 20° slope. The block has coefficients of friction Mus = 0.64 and Muk = 0.54 with the surface of the slope. It is connected using a very light string over an ideal pulley to a hanging block of mass 2.0 kg. The string above the slope pulls parallel to the surface. What is the minimum mass m so the system will remain at rest when it is released from rest? A) 2.1 kg B) 3.3 kg C) 1.3 kg D) 3.6 kg
a
The space shuttle, in circular orbit around the Earth, collides with a small asteroid which ends up in the shuttle's storage bay. For this collision, (a) only momentum is conserved (b) only kinetic energy is conserved (c) both momentum and kinetic energy are conserved (d) neither momentum nor kinetic energy is conserved
a
Two children are balanced on opposite sides of a seesaw. If one child leans inward toward the pivot point, her side will a) rise b) fall c) neither rise nor fall
a
Which one of the following is an accurate statement? a) the ratio of tensile stress to tensile strain is called Young's modulus b) strain has a meaning very close to force c) stress has a meaning very close to stretch d) tensile stress is measured in newtons e) tensile strain is measured in meters
a
You are lying in bed and want to shut your bedroom door. You have a bouncy "superball" and a blob of clay, both with the same mass. Which one would be more effective to throw at your door to close it? (a) the superball (b) the the blob of clay (c) both the same (d) neither will work
a
You push a heavy crate down a ramp at a constant velocity. Only four forces act on the crate. Which force does the greatest magnitude of work on the crate? (a) friction (b) gravity (c) normal force (d) force of you pushing (e) net force
a
You are trying to push your stalled car. Although you apply a horizontal force of 400 N to the car, it doesn't budge, and neither do you. Which force(s) must also have a magnitude of 400 N? (a) The force exerted by the car on you. (b) The friction force exerted by the car on the road (c) The normal force exerted by the road on you. (d) The friction force exerted by the road on you.
a, b, d
A heavy dart and a light dart are launched horizontally on a frictionless table by identical ideal springs. Both springs were initially compressed by the same amount. Which of the following statements about these darts are correct? a) the darts both have the same KE just as they move free of the spring b) the lighter dart leaves the spring moving faster than the heavy dart c) the heavy dart had more initial elastic potential energy than the light dart d) both darts move free of the spring with the same speed e) both darts had the same initial elastic potential energy
a, b, e
When a rigid object rotates about a fixed axis, what is true about all the points in the object? a) they all have the same angular speed b) they all have the same tangential speed c) they all have the same angular acceleration d) they all have the same tangential acceleration e) they all have the same radial acceleration
a, c
A 5-kg ball collides inelastically head on with a 10-kg ball, which is initially stationary. Which of the following statements is true? a) the magnitude of the change of velocity the 5-kg ball experiences is greater than that of the 10-kg ball b) the magnitude of the change of velocity the 5kg ball experiences is less than that of the 10kg ball c) the magnitude of the change of velocity the 5kg ball experiences is equal to that of the 10kg ball d) The magnitude of the change of momentum of the 5kg ball is equal to the magnitude of the change of momentum of the 10kg ball e) both balls lose all their momentum since the collision is inelastic
a, d
A car accelerates from rest to 30 km/h. Later, on a highway it accelerates from 30 km/h to 60 km/h. Which takes more energy, going from 0 to 30 or 30 to 60? (a) 0 to 30 (b) 30 to 60 (c) both are the same
b
A car speedometer that is supposed to read the linear speed of the car uses a device that actually measures the angular speed of the tires. If larger-diameter tires are mounted on the car instead, how will that affect the speedometer reading? The speedometer: a) will still read the speed accurately b) will read low c) will read high
b
A child whirls a ball in a vertical circle. Assuming the speed of the ball is constant (an approximation), when would the tension in the cord connected to the ball be greatest? (a) at the top of the circle (b) at the bottom of the circle (c) a little after the bottom of the circle when the ball is climbing (d) a little before the bottom of the circle when the ball is descending quickly (e) nowhere; the cord is stretched the same amount at all points
b
A golf ball is hit with a golf club. While the ball flies through the air, which forces act on the ball? Neglect air resistance: (a) The force of the golf club acting on the ball (b) The force of gravity acting on the ball (c) The force of the ball moving forward through the air
b
A railroad car collides with and sticks to an identical railroad car that is initially at rest. After the collision, the kinetic energy of the system a) is the same as before b) is 1/2 as much as before c) is 1/3 as much as before d) is 1/4 as much as before e) is 1/4 as much as before
b
A small boat coasts at constant speed under a bridge. A heavy sack of sand is dropped from the bridge onto the boat. The speed of the boat: (a) increases (b) decreases (c) does not change (d) without knowing the mass of the boat and the sand, we can't tell
b
An object at rest begins to rotate with a constant angular acceleration. If this object rotates through an angle (theta) in time (t), through what angle did it rotate in the time 1/2t? a) 1/2 theta b) 1/4 theta c) theta d) 2 theta e) four times Bonnie's
b
An object hits a wall and bounces back with half of its original speed. What is the ratio of the final kinetic energy to the initial kinetic energy? a) 1/2 b) 1/4 c) 1/8 d) 1/16
b
Two satellites orbit the Earth in circular orbits of the same radius. One satellite is twice as massive as the other. Which statement is true about the speeds of these satellites? (a) the heavier satellite moves twice as fast as the lighter one (b) the two satellites have the same speed (c) the lighter satellite moves twice as fast as the heavier one (d) the ratio of their speeds depends on the orbital radius
b
Two spheres have the same radius and equal mass. One sphere is solid, and the other is hollow and made of a denser material. Which one has the bigger moment of inertia about an axis through its center? a) the solid one b) the hollow one c) both the same
b
Two wheels having the same radius and mass rotate at the same angular velocity. One wheel is made with spokes so nearly all the mass is at the rim. The other is a solid disk. How do their rotational kinetic energies compare? a) They are nearly the same b) the wheel with spokes has about twice the KE c) The wheel with spokes has higher KE, but not twice as high d) The solid wheel has about twice the KE e) the solid wheel has higher KE, but not twice as high
b
While driving fast around a sharp right turn, you find yourself pressing against the car door. What is happening? (a) centrifugal force is pushing you into the door (b) the door is exerting a rightward force on you (c) both of the above (d) neither of the above
b
You push very hard on a heavy desk, trying to move it. You do work on the desk: (a) whether or not it moves, as long as you are exerting a force (b) only if it starts moving (c) only if it doesn't move (d) never - it does work on you (e) none of the above
b
A 10.0 N weight is suspended by two cords as shown in fig 9-44. What can you say about the tension in the two cords? a) The tension in both cords is 5.0 N b) The tension in both cords is equal but not 5.0 N c) The tension in cord A is greater than that in cord B d) The tension in cord B is greater than that in cord A
c
A baseball is pitched horizontally toward home plate with a velocity of 110 km/h. In which of the following scenarios does the baseball have the largest change in momentum? (a) the catcher catches the ball (b) the ball is popped straight up at a speed of 110 km/h (c) the baseball is hit straight back to the pitcher at a speed of 110 km/h (d) scenarios a and b have the same change in momentum (e) scenarios a, b, and c have the same change in momentum
c
A bowling ball is dropped from a height h onto the center of a trampoline, which launches the ball back up into the air. How high will the ball rise? (a) significantly less than h (b) more than h. The exact amount depends on the mass of the ball and the springiness of the trampoline (c) no more than h - probably a little less (d) cannot tell without knowing the characteristics of the trampoline
c
A heavy ball suspended by a cable is pulled to the side by a horizontal force F as shown in Fig 9-43. If angle theta is small, the magnitude of the force F can be less than the weight of the ball because: a) the force holds up only part of the ball's weight b) even though the ball is stationary, it is not really in equilibrium c) F is equal to only the x component of the tension in the cable d) the original statement is not true. To move the ball, F must be at least equal to the ball's weight
c
A man pushes a block up an incline at a constant speed. As the block moves up the incline, (a) its kinetic energy and potential energy both increase (b) its kinetic energy increases and its potential energy remains the same (c) its potential energy increases and its kinetic energy remains the same (d) its potential energy increases and its kinetic energy decreases by the same amount
c
A person stands on a scale in an elevator. His apparent weight will be the greatest when the elevator: (a) is standing still (b) is moving upward at a constant velocity (c) is accelerating upward (d) is moving downward at a constant velocity (e) is accelerating downward
c
A satellite in circular orbit around the Earth moves at constant speed. This orbit is maintained by the force of gravity between the Earth and the satellite, yet no work is done on the satellite. How is this possible? (a) no work is done if there is no contact between objects (b) no work is done because there is no gravity in space (c) no work is done if the direction of motion is perpendicular to the force (d) no work is done if objects move in a circle
c
As you increase the force that you apply while pulling on a rope, which of the following is NOT affected? a) stress on the rope b) the strain on the rope c) the Young's modulus of the rope d) all of the above e) none of the above
c
Bonnie sits on the outer rim of a merry-go-round, and Jill sits midway between the center and the rim. The merry-go-round makes one revolution every 2 seconds. Jills linear velocity is: a) the same as Bonnie's b) twice Bonnie's c) half of Bonnie's d) one-quarter of Bonnie's e) four times Bonnie's
c
In the International Space Station which orbits Earth, astronauts experience apparent weightlessness because (a) the station is so far away from the center of Earth (b) the station is kept in orbit by a centrifugal force that counteracts the Earth's gravity (c) the astronauts and the station are in free fall towards the center of the Earth (d) there is no gravity in space (e) the station's high speed nullifies the effects
c
Suppose an object is accelerated by a force of 100 N. Suddenly a second force of 100 N in the opposite direction is exerted on the object, so that the forces cancel. The object: (a) is brought to rest rapidly (b) decelerates gradually to rest (c) continues at the velocity it had before the second force was applied (d) is brought to rest and then accelerates in the direction of the second force
c
Swimmers at a water park have a choice of two frictionless water slides. Although both slides drop over the same height h, slide 1 is straight while slide 2 is curved, dropping quickly at first and then leveling out. How does the speed v1 of a swimmer reaching the bottom of slide 1 compare with v2, the speed of a swimmer reaching the end of slide 2? a) v1 > v2 b) v1 < v2 c) v1 = v2 d) the heavier swimmer will have a greater speed than the lighter swimmer, no matter which slide he uses e) no simple relationship exists between v1 and v2
c
The solid dot shown in figure 8-36 is a pivot point. The board can rotate about the pivot. Which force shown exerts the largest magnitude torque on the board? a) 1000 N to the far left (by the hinge) b) 500 N to the middle c) 500 N on the far right d) 800 N directly toward the hinge e) 500 N at an angle to the far right
c
Two identical billiard balls traveling at the same speed have a head-on collision and rebound. If the balls had twice the mass, but maintained the same size and speed, how would the rebound be different? (a) at a higher speed (b) at slower speed (c) no difference
c
What causes the boat to move forward? a. The force the man exerts on the paddle. b. The force the paddle exerts on the water. c. The force the water exerts on the paddle. d. The motion of the water itself.
c
You push on box G that is next to box H, causing both boxes to side along the floor, as shown in the figure. The reaction force to your push is: a) the push of box G on box H b) the push of box H on box G c) the push of box G against you d) the upward force of the floor on box G the acceleration of box G
c
Consider a force F = 80N applied to a beam as shown in Fig 8-37. The length of the beam is l (arc length) = 5.0m, and theta = 37 degrees, so that x = 3.0 m and y = 4.0 m. Of the following expressions, which ones give the correct torque produced by the force F around point P? a) 80 N b) (80 N)(5.0 m) c) (80 N)(5.0 m)(sin37) d) (80 N)(4.0 m) e) (80 N)(3.0 m) f) (48 N)(5.0 m) g) (48 N)(4.0 m)(sin37)
c,e,f
A 60-kg woman stands on the very end of a uniform board, of length l, which is supported one-quarter of the way rom one end and is balanced. What is the mass of the board? a) 15 kg b) 20 kg c) 30 kg d) 60 kg e) 120 kg
d
A bear sling is used in some national parks for placing backpackers' food out of the reach of bears. As the backpacker raises the pack by pulling down on the rope, the force F needed: (a) decreases as the pack rises until the rope is straight across (b) doesn't change (c) increases until the rope is straight (d) increases but the rope always sags where the pack hangs
d
A car drives at a steady speed around a perfectly circular track. (a) the car's acceleration is zero (b) the net force on the car is zero (c) both the acceleration and net force on the car point outward (d) both the acceleration and net force on the car point inward (e) if there is no friction, the acceleration is outward
d
A car goes around a circular curve on a horizontal road at constant speed. What is the direction of the friction force on the car due to the road? a) tangent to the curve in the forward direction b) tangent to the curve opposite to the direction of the car's motion c) perpendicular to the curve outward d) perpendicular to the curve inward e) there is no friction on the car because its speed is constant
d
A car traveling at a velocity v can stop in a minimum distance d. What would be the car's minimum stopping distance if it were traveling at a velocity of 2v? (a) d (b) sq 2d (c) 2d (d) 4d (e) 8d
d
A merry go round spins freely when Diego moves quickly to the center along a radius of the merry go round. As he does this a) the moment of inertia [I] decreases and the angular speed increases b) [I] decreases and angular speed decreases c) [I] decreases and angular speed remains same d) [I] increases and angular speed increases e) [I] increases and angular speed decreases
d
A parking garage is designed for two levels of cars. To make more money, the owner decides to double the size of the garage in each dimension (length, width, and number of levels). For the support columns to hold up four floors instead of two, how should he change the columns' diameter? a) double the area of the columns by increasing their diameter by a factor of 2 b) double the area of the columns by increasing their diameter by a factor of the sq rt of 2 c) quadruple the area of the columns by increasing their diameter by a factor of 2 d) increase the area of the columns by a factor of 8 by increasing their diameter by a factor of 2*sq rt of 2 e) he doesn't need to increase the diameter of the columns
d
A person sits on a freely spinning lab stool that has no friction in its axle. When this person extends her arms, a) the moment of inertia [I] decreases and the angular speed increases b) [I] decreases and angular speed decreases c) [I] increases and angular increases d) [I] increases and angular speed decreases e) [I] increases and angular speed remains the same
d
A push of magnitude P acts on a box of weight W as shown in the figure. The push is directed at an angle θ below the horizontal, and the box remains a rest. The box rests on a horizontal surface that has some friction with the box. The normal force on the box due to the floor is equal to a) W b) W + P c) W + Pcosθ d) W + Psinθ e) W - Psinθ
d
A rubber band is stretched by 1.0 cm when a force of 0.35 N is applied to each end. If instead a force of 0.70 N is applied to each end, estimate how far the rubber band will stretch from its unstretched length: a) 0.25 cm b) 0.5 cm c) 1.0 cm d) 2.0 cm e) 4.0 cm
d
A small car and a heavy pickup truck are both out of gas. The truck has twice the mass of the car. After you push both the car and the truck for the same amount of time with the same force, what can you say about the momentum and kinetic energy of the car and the truck? Ignore friction. (a) they have the same momentum and the same KE (b) the car has more momentum and more KE than the truck (c) the truck has more momentum and more KE than the car (d) they have the same momentum, but the car has more kinetic energy than the truck (e) they have the same kinetic energy, but the truck has more momentum than the car
d
A truck going 15 km/h has a head-on collision with a small car going 30 km/h. Which statement best describes the situation? (a) the truck has the greater change of momentum because it has the greater mass (b) the car has the greater change of momentum because it has the greater speed (c) neither the car nor the truck changes its momentum in the collision because momentum is conserved (d) they both have the same change in magnitude of momentum because momentum is conserved (e) none of the above is necessarily true
d
An object is moving with constant non-zero velocity. Which of the following statements about it must be true? a) a constant force is being applied to it in the direction of motion b) a constant force is being applied to it in the direction opposite of motion c) a constant force is being applied to it perpendicular to the direction of motion d) the net force on the object is 0 e) its acceleration is in the same direction as its velocity
d
Matt, in the foreground of (Figure 1), is able to move the large truck because: (a) he is stronger than the truck (b) he is heavier in some respects than the truck (c) he exerts a greater force on the truck than the truck exerts back on him (d) the ground exerts a greater friction force on Matt than it does on the truck (e) the truck offers no resistance because its breaks are off
d
Satellite A has twice the mass of satellite B, and moves at the same orbital distance from Earth as satellite B. Compare the speeds of the two satellites. a) B is twice the speed of A b) B is 1/2 the speed of A c) B is 1/4 the speed of A d) B is equal to A e) B is 4 times the speed of A
d
Two small balls, A and B, attract each other gravitationally with a force of magnitude F. If we now double both masses and the separation of the balls, what will now be the magnitude of the attractive force on each one? a) 16F b) 8F c) 4F d) F e) F/4
d
When is the angular momentum of a system constant? a) only when its total KE is constant b) only when no net external force acts on the system c) only when the linear momentum and the energy are constant d) only when no net external torque acts on the system e) only when the moment of inertia is constant
d
When is the angular momentum of a system constant? a) only when its total kinetic energy is constant b) only when no net external force acts on the system c) only when the linear momentum and the energy are constant d) only when non net external torque acts on the system e) only when the moment of inertia is constant
d
When you apply the torque equation ET=0 to an object in equilibrium, the axis about which torques are calculated a) must be located at a pivot b) must be located at the object's center of gravity c) should be located at the edge of the object d) can be located anywhere
d
When you apply the torque equation sumT=0 to an object in equilibrium, the axis about which torques are calculated a) must be located at a pivot b) must be located at the object's center of gravity c) should be located at the edge of the object d) can be located anywhere
d
You are pushing a heavy box across a rough floor. When you are initially pushing the box and it is accelerating, (a) you exert a force on the box, but the box does not exert a force on you (b) the box is so heavy it exerts a force on you, but you do not exert a force on the box (c) the force you exert on the box is greater than the force of the box pushing back on you (d) the force you exert on the box is equal to the force of the box pushing back on you (e) the force that the box exerts on you is greater than the force you exert on the box
d
tensile stress is a) the strain per unit length b) the same as force c) the ratio of the change in length d) applied force per cross-sectional area
d
A ball is thrown straight up. At what point does the ball have the most energy? (a) at the highest point (b) when it is first thrown (c) just before it hits the ground (d) when the ball is halfway to the highest point of its path (e) everywhere; the energy of the ball is the same at all of these points
e
A woman is balancing on a high wire which is tightly strung as shown in Fig. 9-45. The tension in the wire is a) about half the woman's weight b) about twice the woman's weight c) about equal to the woman's weight d) much less than the woman's weight e) much more than the woman's weight
e
Jill does twice as much work as Jack does and in half the time. Jill's power output is a) the same as Jack's power output b) 1/4 as much as Jack's power output c) 1/2 as much as Jack's power output d) twice Jack's power output e) 4 times that of Jack's power output
e
Which of the following point towards the center of the circle in uniform circular motion? (a) acceleration (b) velocity, acceleration, net force (c) velocity, acceleration (d) velocity, net force (e) acceleration, net force
e
Which pulls harder gravitationally, the Earth on the Moon, or the Moon on the Earth? Which accelerates more? (a) the Earth on the Moon; the Earth (b) the Earth on the Moon; the Moon (c) the Moon on the Earth; the Earth (d) the Moon on the Earth; the Moon (e) both the same; the Earth (f) both the same; the Moon
f
A disk, a hoop, and a solid sphere are released at the same time at the top of an inclined plane. They are all uniform and roll without slipping. In what order do they reach the bottom?
sphere, disk, hoop
A skier starts from rest at the top of each of the hills shown in the figure. On which hill will the skier have the highest speed at the bottom assuming a small amount of friction:
the steepest hill and the longest hill