Physics - learning catalytics midterm 2
1 Suppose you are standing on a bathroom scale when you are flying in a jet airplane. For a moment the scale reads more than your actual weight. During that moment, it's exerting an upward force on you that is greater than your weight and you are accelerating upward. accelerating downward. not accelerating. accelerating sideways.
A
11 When you throw a tennis ball against the floor at an angle, the direction of the vertical component of its velocity reverses. the horizontal component of its velocity reverses. the speed of the ball reverses. the vertical component of its velocity doubles.
A
12 Consider an elastic ball that is falling downward toward the ground. The ball hits the ground and then begins traveling upward again. At what point in the trip does the ball have the most energy stored in it as elastic potential energy? At the bottom of the path when it is not moving, right before it rebounds. After it has rebounded and left the ground. Right before it hits the ground When it is moving the fastest.
A
13 For an object that sinks in a fluid, The weight of fluid displaced is less than its weight. The weight of the fluid displaced is greater than the object's weight. The weight of the fluid displaced equals the object's weight. The weight of the object becomes more than in air.
A
6 It is important for cyclists to lean their bicycles while negotiating sharp turns because the torque created by their leaning balances out the frictional torque from the road which would tend to flip them. the torque created by their leaning balances out their weight and holds them up. their tires flatten out, thus getting better traction on the road. they increase their static stability
A
7 Which system is in a state of stable equilibrium? A marble in the bottom of a spherical bowl. A Marble on top of a spherical bowl. A marble on a flat, level surface. A marble rolling down an inclined surface.
A
A 45 caliber bullet is fired out of a gun toward the BACK of a plane. The bullet travels at 545 mph and the plane is flying at a speed of 540 mph. How fast is the bullet traveling relative to an observer standing on the ground watching? 5 mph 540 mph 545 mph 1085 mph Impossible to tell how fast.
A
Having examined the various balancing toys at the front of the room, what characteristic makes them work? The center of gravity is below the pivot point and outside the toy. The center of gravity is directly over the pivot and near the middle of the toy. There are two centers of gravity, one on either side of the pivot.
A
In a popular classroom demonstration, a cotton ball is placed in the bottom of a strong test tube. A plunger fits inside the tube and it makes an air - tight seal. It is then pushed down very rapidly, and the cotton flashes and burns. This happens because when the air was compressed its temperature increased. friction between the plunger and the tube ignited the cotton. cotton contains a pressure - sensitive substance that burns upon impact. it's one of those demos that nobody understands.
A
Two syringes are filled with water and connected with a tube so no air is contained within either syringe or the tube. When the small plunger is depressed the full distance, what happens to the large plunger? It moves less distance than the small plunger. It moves the same distance as the small plunger. It moves an even greater distance than the small plunger.
A
Water flows out of a series of holes in the side of a tank. The flow rate is the greatest for The largest hole. one of the intermediate holes The smallest hole.
A
Water flows out of two holes in the side of a tank. The flow rate is the greatest for The larger hole. The smaller hole. It depends on the depth of the water.
A
You stop for a cappuccino at a coffee shop and notice that the tiny white bubbles of steamed milk remain on the surface of the coffee. These air-filled bubbles stay where they are, rather than descending into the coffee or rising into the air, because they are less dense than the coffee but more dense than the air above the coffee. more dense than the coffee but less dense than the air above the coffee. lighter than the cup of coffee but heavier than the column of air above the coffee. thicker than the coffee but less thick than the air above the coffee.
A
As you walk on level ground, what path does your hip make relative to the planted foot (the one that is supporting your weight)?
A circle
14 You are riding a very fast Ferris Wheel so that you actually notice a variation in your apparent weight. Where is your apparent weight maximum? At the top At the bottom Halfway up, going down Halfway up, going up
B
16 A bathroom scale reads: Your weight Your apparent weight The force with which the earth attracts you Your mass in kg
B
17 A popular drink is composed by pouring several types of beverage (one on top of the other) in order to get a layering effect. In what order should the individual beverages be poured into the glass so that your drink is stable? Least dense first and then in order of increasing density. Most dense first and then in order of decreasing density. Most dense on the top and bottom to hold the least dense fluids in the middle. Not enough information is given
B
21 A top is Statically stable and dynamically unstable. Statically unstable and dynamically stable. Statically unstable and dynamically unstable. Statically stable and dynamically stable.
B
22 Suppose you are spending your weekend on roller skates trying to get momentum from somewhere. Which of the following will give you momentum in the south direction? Throwing your keys southward. Throwing your keys northward. Bending down and throwing your keys straight up. (B) or (C).
B
4 If, at the instant shown, the car hit an oily patch (no friction), what direction would it travel in the image? to the right straight down to the left. in a curve toward the bottom and left.
B
5 Suppose you had a very long straw that could reach from a cup of water on the ground level to the top of a very tall building. When you suck on the straw in order to bring water up, You could drink the water at any height with no problem You could bring the water up to only a certain height in the straw because the atmosphere pushes down on the surface of the water by a given amount. You could bring the water up to only a certain height in the straw because after it will flash freeze in the cup. Water is too thick to be pulled up in the straw by more than a few inches.
B
A rocket accelerates upward at launch because: It is pushing on the launch pad and the launch pad pushes back. The rocket is pushing on the water and the water pushes back on the rocket.
B
Astronauts in the space shuttle feel weightless because They are so far away from the center of the Earth. they are in a constant state of free - fall. they are moving very rapidly. there is no atmosphere where they are.
B
Cars are designed so that their bodies buckle (permanently deform) when they are in an accident. How does the buckling make the car safer by not allowing it to recoil (bounce) so much? The buckling stores energy. The buckling dissipates the energy of the crash. The buckling provides energy to the crashing objects. The buckling gives the car a high coefficient of restitution.
B
For your high school science project you are able to get community support and terraform Mars, so that liquid water could exist on its surface. Suppose you have two cans of soda - one barely floats and one barely sinks in fresh water on Earth. Taking them to Mars, with the gravitational acceleration being 1/3 its value on earth, Both objects will now float because they are lighter. The buoyant behavior of the two objects will be the same. Both objects will sink because the water is lighter. The one that sank will now float and the one that floated will now sink.
B
If the flow rate of water through a hose is Area * speed then what will happen when you put your thumb over the opening of the faucet in your sink at home? The water will just trickle out. The water will shoot out past your thump at much higher speed.
B
The pressure gradient set up in water standing is a glass is an example of ________ ________ in pressure, while variations in pressure due to water flowing faster in the smaller parts of a pipe are a type of ________ ________ in pressure. static variation; buoyant force static variation; dynamic variation dynamic variation; constant value dynamic variation; dynamic constancy
B
Water flows out of two holes in the side of a tank. The larger hole is 1.5 times the diameter of the smaller hole. The flow rate for the larger hole is: About half as much as for the smaller hole. about twice as much as for the smaller hole. About four times as much for the smaller hole.
B
You are awakened in your hotel room late one night to the sound of an explosion. You realize your door is ajar and you can just see the fireball from the explosion racing down the hallway toward your door. You have one chance to close the door before the fireball gets there and, just by chance, there are two balls on the night stand. Both have the same mass but one is a soft clay ball and the other is a super bouncy ball. Which do you throw at the door in hopes it will close in time? The clay ball. The super ball. Neither because there is no chance either of the balls can close the door.
B
You are extremely bored during the long summer months when school is out of session, so you decide to attach a graphing calculator to a rubber band and repeatedly bounce it up and down vertically. When the rubber band is at its maximum stretch away from your hand the calculator's velocity is downward but its acceleration is upward. the calculator's velocity is zero but its acceleration is upward. the calculator's velocity is upward but its acceleration is downward. the calculator's velocity is zero but its acceleration is downward.
B
You now remove all the weight from the spring. What will the the length be with no weight? Slightly longer than before any weights were added. The same length as it was before any weights were added. The same length as when the two weights were hanging from it - once stretched it is permanently stretched.
B
15 Some engineers have suggested that we can simulate gravity in outer space by having a circular rotating space station where persons feel an outward - directed fictitious force due to the rotation of the station. The reason they feel such a force is because their velocity is toward the center of the space station and their inertia tends to keep them moving outward. the fictitious force is always in the direction of centripetal acceleration. they are accelerating toward the center of the space station and inertia tends to keep them moving sideways. their velocity is away from the center of the space station and their inertia tends to make them move in towards the center.
C
18 At various times in the news it has been reported that certain vehicles are susceptible to rolling over. The physical mechanism that is responsible for rollovers is Frictional torques about the driver only. Frictional torques from the vehicle on the road acting below the road's center of mass. Frictional torques from the road on the vehicle about its center of mass, which is higher in taller vehicles. Strong air currents simply blowing the vehicle over.
C
9 For an object that is neutrally buoyant in a fluid, The weight of fluid displaced is less than its weight. The weight of the fluid displaced is greater than the object's weight. The weight of the fluid displaced equals the object's weight. The object has zero weight.
C
A planet orbits a star such that Its sun is at the center of the orbit at all times. Its sun is at one of the foci of the eliptical orbit while that planet is at the the other. Its sun is at the one of the foci while the planet travels in an elliptical path.
C
Given a long stick, it is easier to balance on one end on a finger tip when: It is just the stick alone. When the stick has extra mass close to the finger lowering the center of mass and decreasing rotational inertia. When the stick has extra mass near the far end, raising the center of gravity but increasing the rotational inertia.
C
Given the forces acting on the board, what keeps the board from rotating? The sum of all forces is zero. The rotational inertia of the board keeps it from rotating. The sum of all torques acting on the board is zero.
C
Water flows out of a series of holes in the side of a tank. The flow rate is the greatest for The highest (shallowest) hole. one of the intermediate holes The deepest hole.
C
What will happen when the two objects orbiting each other have nearly the same mass? Each one will be at a focus of the ellipse They will fall into each other and become one. They will orbit about the center of mass of the two objects
C
A 45 caliber bullet is fired out of a gun toward the FRONT of a plane. The bullet travels at 545 mph and the plane is flying at a speed of 540 mph. How fast is the bullet traveling relative to an observer standing on the ground watching? 5 mph 540 mph 545 mph 1085 mph Impossible to tell how fast.
D
Once the string is cut, predict where the puck will strike the "walls" of the table. It will move direct out from the center and strike somewhere along the rail at the bottom of the image. It will move directly "up" along the string and strike the post holding the string. It will curve around the center post and will strike the rail on the left in the video but above it's current position. It will travel in a straight line, parallel to the rail on the bottom and strike the rail on the left.
D
You are riding a multi-speed bicycle up a steep hill that's 100 m high and want to do as little work as possible on your way up the hill. You should choose the largest crank sprocket (attached to the pedals) and the smallest freewheel sprocket (attached to the rear wheel). You should choose the smallest crank sprocket (attached to the pedals) and the largest freewheel sprocket (attached to the rear wheel). You should choose the largest crank sprocket (attached to the pedals) and the largest freewheel sprocket (attached to the rear wheel). Your choice of gears doesn't matter because you'll do the same amount of work climbing the hill no matter which gear you choose.
D
You hang a weight from a spring and it stretches 2 inches. Then you add a second identical weight to the spring, The total stretch in the spring will be 1 inch 2 inches 3 inches 4 inches 5 inches
D
You work with a catering firm and have been given a challenge. By emptying several liquid beverage dispensers, you have to rank them in order of their content (which one is fullest, next fullest, etc.) Having had a physics class, you devise a scheme to compare the speeds of the fluids exiting the spouts at the bottom of the containers. The principle you base your prediction on is: the volume is lower so the speed is lower. what were you thinking!? The speeds won't depend upon fluid level the speed increases when there is more air in the jug. the pressure (and hence water level) is lower when the speed is lower.
D
23 The maximum speed a rocket can achieve is the speed of light the speed of sound. equal to the speed of its exhaust plume. less than the speed of its exhaust plume. greater than the speed of its exhaust plume but less than the speed of light.
E
What is the pressure just under the surface a container filled with water?
Gravity pulls the air down and as you increase in altitude there is less air above to push down on you.
Why is the atmospheric pressure at the surface of the Earth greatest and then decreases as you gain altitude?
Gravity pulls the air down and as you increase in altitude there is less air above to push down on you.
Predict the shape of the graph of pressure versus depth in a body of water.
Straight line with a positive slope
How did the egg end up inside the bottle?
The air pressure outside was greater than the air pressure inside.
What crushed the pop can?
The air pressure outside was greater than the air pressure inside.
Why did the hot air balloon rise?
The bouyant force was greater than the weight of the balloon.
Why does the cartesian diver sink?
The bouyant force was less than the weight of the diver.
Why was the pressure inside the pop can less than the atmospheric pressure outside?
The cold water bath quickly cooled the gas inside the can reducing the air pressure inside.
