integrated science b - unit 2: force lessons 6-9
marcella throws a 1 kg tub of ice cream with a net force of 10 n. what is the acceleration of the ice cream?
10 m/s2
a metal object is at rest on a surface. a magnet is exerting a force on it to the left while the object remains at rest. which of the following force diagrams correctly models this situation?
https://cdstools.flipswitch.com/asset/media/538951
which force is an attractive force that is affected by the masses of objects?
gravitational force
which forces do not require contact between objects in order to exert a push or pull? select all that apply
gravitational force between the earth and an object magnetic force between two magnets
a rock falls off the edge of a cliff, speeding up as it falls. which of the following choices correctly models the force diagram for the rock during its fall?
https://cdstools.flipswitch.com/asset/media/539337
"an object at rest or in motion will stay at rest or in motion unless acted on by an unbalanced force." this statement is known as
newton's 1st law
according to __________, an object at rest or motion stays at rest or in motion unless acted on by an unbalanced force.
newton's 1st law
lesson 7
newton's first and second law
which of the following laws can be described as, "within every force interaction, each object exerts the same amount of force on the other object, but in the opposite direction."
newton's third law
lesson 8
newton's third law of motion
look at the image below. what is the net force acting on the crate?
0 n
study the image of a boat placed in water. what is the net force on the boat?
0 n
a rock exerts 5000 pa of pressure on the ground. if the rock weighs 250 n, how much area is in contact with the ground?
0.05 m2
a ball is moving at a speed of 5 mi/h along a frictionless surface. It will continue moving at this speed as long as ____ select all that apply
0.25 of 1 balanced forces act up on it, because an unbalanced force will change its motion something keeps pulling it, because it requires a force to continue its motion
a truck accelerates 2 m/s2 when it is empty. if the truck is filled so that it has twice the mass and the same amount of net force is applied, how much will the truck accelerate?
1 m/s2
study the scenario. a marble is rolled across the floor with a force of 2 n to the left. there is 1 n of friction acting on the marble to the right. what is the net force acting on the marble?
1 n to the left
study the scenario. a boy kicks a ball with a mass of 5 kg so that it accelerates at 4 m/s2 in the forward direction. what is the force that the ball exerts on the boy?
20 n backward
an astronaut is floating in space. he throws a baseball with a force of 20 n to the right, while the baseball pushes the astronaut with a force of 20 n to the left. what is the net force on the astronaut?
20 n, left
a cabinet weighing 100 n is placed on a floor. the amount of contact area between the cabinet and the floor is 0.5 m2. how much pressure does the cabinet exert on the floor?
200 pa
a girl throws a 2 kg rock with a net force of 6 n. what is the acceleration of the rock?
3 m/s2
a block of wood weighing 25 n is submerged under water. if the net force on the wood is 5 n upward, how much buoyant force is acting on the wood?
30 n upward
a giant squid is accelerating through the ocean at 0.5 m/s2. if the mass of the squid is 800 kg, what is the magnitude of the net force?
400 n
study the scenario. a suitcase with a weight of 200 n falls overboard off of a cruise ship, and displaces 150 n of water. which statement correctly gives the net force acting on the suitcase and describes what happens to it?
50 n downward, it sinks
a 1 kg object is floating in water. what is the weight of the object?
9.8 n
examine the scenario. a book with a mass of 1 kg is sitting on a desk. how much gravitational force is acting on the book?
9.8 n
a horse pulls a carriage with a force of 90 n forward. what is the reaction force of the carriage on the horse?
90 n backward
study the scenario. a scientist observes that the smoother he makes a surface, the further a ball will roll along it before coming to a stop. he imagines that if he could make the surface perfectly smooth, the ball would roll forever. what can be concluded about the motion of objects from these observations?
a continual force is not necessary in order to keep an object in a state of motion.
which options correctly describe a tension force? select all that apply
a force equal and opposite to the gravitational force for a hanging object a force that increases when the mass of a hanging object increases a force transmitted through ropes, strings, wires, or cables
study the scenario. an object is at rest. at five seconds, someone comes over and pushes the object with a force of 3 N to the right. which of the following choices describes the force needed to keep the object in static equilibrium?
a force of 3 n to the left must be exerted on the box at exactly 5 seconds, so that the forces are balanced and the object remains at rest.
study the scenario. an object is at rest. at ten seconds, someone comes over and pushes the object with a force of 5 n, to the left. which of the following choices describes the force needed to keep the object in static equilibrium?
a force of 5 n to the right must be exerted on the box at exactly 10 seconds, so that the forces are balanced and the object remains at rest.
which option(s) would correctly describe normal force? select all that apply
a supportive force that acts at right angles to a surface and helps support an object sitting on that surface a contact force
which of the following experiments could be used to test newton's third law of motion?
aim a projectile at a target and measure the force of the projectile on the target and the force of the target on the projectile.
study the image. which of the following choices best explains when an unbalanced force is acting on the object described in the graph?
an unbalanced force acts on the object from 0 seconds to 4 seconds because the object is accelerating. the slope indicates a changing velocity only for the first 4 seconds.
study the image. which of the following choices correctly describe the effect of the unbalanced force on the motion represented in the graph?
an unbalanced force is acting on the object the entire time because the object is accelerating the entire time. Since it's slowing down, the unbalanced force is opposite to the direction of the object's motion.
the normal force can be defined as
an upward force between a surface and object, always perpendicular to the surface
mercury is a metal that is liquid at room temperature. it has a density of 13.7 g/cm3. older american pennies are made mostly of copper and have a density of 8.8 g/cm3, newer pennies are made mostly of zinc and have a density of 7.2 g/cm3. what will happen to a new and an old American penny if dropped into a beaker of mercury?
both pennies will float, since they both have densities less than that of liquid mercury.
two identical suitcases are thrown into a swimming pool, and sink to the bottom. one of the suitcases is filled with bricks, the other with bubble wrap. which of the following correctly describes the buoyant force on the two suitcases?
both suitcases have the same buoyant force acting on them.
the vector addition rule includes which of the following statements? select all that apply
consider up and right pointing vectors as positive add together only opposite pointing vectors consider left and down pointing vectors as negative
which of the following correctly summarizes newton's third law of motion?
every action has an equal and opposite reaction.
a skydiver is falling at constant velocity. if a force of 600 n is pulling down on the skydiver, how much force must be acting upward on the skydiver?
exactly 600 n
which of the following formulas correctly describes newton's second law?
f = ma
lesson 6
forces
lesson 9
forces in fluids
if a swimmer pushes water backwards, in which direction does that water exert a force on the swimmer?
forwards, because action-reaction forces are directed in opposite directions.
study the image. which option most accurately describes the image?
free-body diagram
a net force of 10 n downward is acting on a falling ball. which of the following force diagrams represents some possible forces acting on the ball? select all that apply
https://cdstools.flipswitch.com/asset/media/539341 https://cdstools.flipswitch.com/asset/media/539342
which of the following images shows unbalanced forces? select all that apply
https://cdstools.flipswitch.com/asset/media/539350 https://cdstools.flipswitch.com/asset/media/539361
an asteroid is travelling through the solar system at a constant velocity. which of the following choices correctly models the forces acting on the asteroid?
https://cdstools.flipswitch.com/asset/media/539365
a person is standing to the left of a heavy crate and pushing to the right on it in order to try to move it. the person exerts a force of 200 n on the crate, but the crate does not budge. which of the following force diagrams best represents the action-reaction pair of forces between the person and the crate?
https://cdstools.flipswitch.com/asset/media/544154
a person is standing to the left of a heavy couch and pulls the couch with a force of 50 n across the floor so that it accelerates 0.1 m/s2. which of the following force diagrams best represents the action-reaction pair of forces between the person and the couch?
https://cdstools.flipswitch.com/asset/media/544170
a man pushes a lawnmower to the right across a grassy surface. which of the following force diagrams best represents the action-reaction pair of forces between the lawnmower and the grassy surface.
https://cdstools.flipswitch.com/asset/media/544183
a hockey puck moves along an icy surface at constant speed. which of the following force diagrams best represents the action-reaction pair of forces between the hockey puck and icy surface?
https://cdstools.flipswitch.com/asset/media/544188
a girl jumps up, exerting a force downward against the ground. which of the following force diagrams best represents the action-reaction pair of forces between the girl and ground?
https://cdstools.flipswitch.com/asset/media/544209
a pirate's chest is sitting on the bottom of the sea. which force diagram best represents the forces acting on the chest while it's at rest under water?
https://cdstools.flipswitch.com/asset/media/544248
a hollow sphere is immersed in water. the sphere's density is less than the density of water. which of the following force diagrams best represents the forces acting on the sphere while it is immersed in water?
https://cdstools.flipswitch.com/asset/media/544267
an anvil is at rest on the ground. which of the following choices correctly models the forces that could be acting on the anvil?
https://cdstools.flipswitch.com/asset/media/544527
an unbalanced force is defined as a force that
is not canceled out by one or more other forces acting in other directions
in water flowing through a drain pipe, as the speed of the water increases, what happens to the pressure?
it decreases.
according to newton's second law, if you double the force applied to an object, but the mass of the object stays the same, what happens to acceleration?
it doubles
read the scenario. pirates drag a treasure chest to the left across a sandy beach. in which direction does the treasure chest experience a frictional force, and why?
it experiences a frictional force to the right because friction always opposes the direction of an object's motion.
study the scenario. as a spacecraft moves beyond pluto, its thrusters are turned on for a short time to boost its speed to approximately 32,500 mi/h. the thrusters are then turned off. if no other forces ever act on the spacecraft what will it do?
it will continue moving at 32,500 mi/h the same direction because forces are not required for an object to continue its motion
read the scenario. a boulder with a mass of 50 kg is sitting in a backyard. if the boulder were half the mass, what could be said about the gravitational force on the boulder?
it would be cut in half.
a hockey puck is sliding at a speed of 20 mi/h along a frictionless surface. it will continue moving at this speed as long as
no forces act upon it, because its inertia will allow it to continue moving at constant velocity
what is the name for a supporting force that acts upward and in a direction perpendicular to a surface?
normal force
which of these lines represents an object with the greatest acceleration, and which represents the object with the least inertia?
object a has the greatest acceleration because the slope of its line is greatest. object a also has the least inertia because it is not resisting a change in its motion as much as the other objects.
the amount of force applied per unit area is known as which of the following?
pressure
what type of force would be responsible for holding up a lamp hanging from the ceiling?
tension force
buoyancy can be defined as
the ability of a fluid to cause an object to float or suspend in it.
which of these is the correct definition of pressure?
the amount of force per unit area
which of these is the correct definition of area?
the amount of space an object covers on a flat surface
a boy picks up a bowling ball. which of the following choices correctly describes the interaction between the boy and the bowling ball?
the boy exerts an upward force on the ball, and the bowling ball exerts a downward force on the boy. both forces are equal in strength.
if a 50 n force is exerted by a shopper on a shopping cart to push it forward, what force is exerted by the cart on the shopper?
the cart would exert a 50 n force backward on the shopper because the cart and the shopper are part of an action-reaction force pair.
a 30 n crate is submerged in water. the amount of buoyant force acting on the crate is 25 n. what will the crate do?
the crate will sink and accelerate downwards. the buoyant force acting upwards on the crate is smaller than the downward force of gravity on the crate.
a large spiny tropical fruit falls and hits a person standing under the tree directly on the head. which of the following statements correctly represents newton's third law in this interaction?
the force the fruit exerts on the person's head is the same strength as the force the person's head exerts on the fruit. the forces are directed in opposite directions.
a student measures the mass and gravitational force on one textbook. if you double the mass by using two textbooks, what would happen to the gravitational force?
the force would double
which of the following correctly explains how air exerts pressure on us?
the molecules in the air located above us are pulled down towards the earth by gravity, causing a downward pressure on objects below.
a hammer hits a nail with a force of 50 n to the right, and the nail accelerates. which of the following statements correctly represents newton's third law and the interaction between the nail and hammer?
the nail exerts 50 n of force to the left on the hammer because these two forces are an action-reaction pair.
you push on a box with a net force of 5 n and it accelerates. what happens if you exert the same net force on an object that has half the mass?
the object will accelerate twice as much.
a person exerts 80,000 pa of pressure on the ground while standing on both feet. what would happen to the pressure if the person then stood on only foot, decreasing the area in contact with the floor to half the original?
the person would exert twice as much pressure on the floor, 160,000 Pa. As the contact area between the surface and object decreases, the pressure increases.
if the pressure on the top of a container of fluid is increased by 10 pa, what will happen to the pressure at the bottom of the container?
the pressure at the bottom of the container increases by 10 pa because fluid pressure is transmitted equally to all points in the fluid.
a 1000 kg of rocks sitting on the ground is spread out over an area of exactly one square meter. what would happen to the pressure on the ground if the rocks were spread out to cover two square meters?
the pressure becomes half as much because the area the force is exerted over has doubled. as the area increases, the pressure decreases.
the pressure on a fluid at rest in a pipe increases by 20 pa. how does this change in pressure affect the pressure on the fluid in the rest of the pipe?
the pressure on all the fluid in the pipes increases by 20 pa because fluid pressure is transmitted undiminished to all points in the fluid.
considering newton's first law of motion, what is the best way to relate a stationary object and a moving object?
they obey exactly the same law of motion since they can both be the same object when considered from different perspectives.
study the image. in which direction will this penguin accelerate?
to the left
a box moves to the right along a rough, wooden surface. in which direction does the box experience a frictional force?
to the left, in the opposite direction of the object's motion
the gravitational force between an object and a planet is known as
weight
