Physics

At the start of a race, a horse accelerates out of the gate at a rate of 3.00 m/s2. How long 𝑡 does it take the horse to cover the first 15.0 m of the race?

CH2 Q3

Two trains, traveling toward one another on a straight track, are 350 m apart when the engineers on both trains become aware of the impending collision and hit their brakes. The eastbound train, initially moving at 97.0 km/h, slows down at 3.90 m/s2. The westbound train, initially moving at 125 km/h, slows down at 4.40 m/s2. If the trains stop before colliding, what is the distance 𝑑 separating them once they stop? If the trains do not stop before colliding, what initial separation 𝑑 would have been needed to avert a disaster?

Ch 2 Q4

Saturn rotates once per 0.444 days. What is the period of rotation of Saturn in seconds? What is the angular velocity of Saturn? Given that Saturn has a radius of 58.2×106 m at its equator, what is the linear velocity at its surface?

Ch 9 hw 1

You decide to travel by car for your holiday visits this year. You leave early in the morning to avoid congestion on the roads. This enables you to drive at a comfortable speed of 𝑣1=65.3 mph for 𝑡1=2.08 hours. However, after this time, you unexpectedly come to a stop for 𝑡stop=35.3 min. Traffic starts moving again and you finish your travel at 𝑣2=55.2 mph for an additional 𝑡2=1.55 hours. There are 1609 meters in one mile. What was the total distance 𝑑 traveled? What was the average speed v?

Ch2 Q7

While standing at the edge of a building's roof, Chad throws an egg upward with an initial speed of 7.00 m/s. The egg subsequently smashes on the ground, 14.0 m beneath the height from which Chad threw it. Ignore the effects of air resistance. At what speed v does the egg pass the point from which it was thrown? How much time t does the egg spend in the air? What total distance d does the egg travel?

Ch2 hw Q 1

A person is driving a car down a straight road. The instantaneous acceleration is constant and directed opposite the direction of the car's motion. The speed of the car is increasing. decreasing. increasing but will eventually decrease. constant. decreasing but will eventually increase.

Ch2 hw Q 18

A gnat takes off from one end of a pencil and flies around erratically for 26.6 s before landing on the other end of the same pencil. If the gnat flew a total distance of 4.65 m, and the pencil is 0.0963 m long, find the gnat's average speed and the magnitude of the gnat's average velocity.

Ch2 hw Q10

An airplane flies eastward and always accelerates at a constant rate. At one position along its path, it has a velocity of 27.9 m/s . It then flies a further distance of 43700 m , and afterwards, its velocity is 44.7 m/s . Find the airplane's acceleration.

Ch2 hw Q11

You notice a one-dimensional-thinking snail crawling along one rail of a railroad track. Naturally, you move it to a safer place. But before you do, you observe it as it moves from position 𝑥i=−99.9 cm to position 𝑥f=−51.7 cm along the rail, as measured from a nearby joint between two segments of rail. What is the magnitude of the snail's displacement, Δ𝑥,in centimeters?

Ch2 hw Q12

ball is dropped from rest at a height of 15.0 m above the ground. Ignore the effects of air resistance. What is the speed 𝑣 of the ball when it is 10.0 m above the ground? How much time 𝑡 is required for the ball to reach the ground level?

Ch2 hw Q13

A driver is traveling at 34.5 m/s on a straight road when he sees a moose standing in the road 82.0 m ahead. The driver of the car slams on the brakes. What is the magnitude 𝑎 of the smallest acceleration 𝐚⃗ that will allow the driver to stop short of the moose and avert an accident? Let the +𝑥 direction be toward the moose. (In British Columbia, Canada, alone, there are over 4000 moose-car accidents each year.)

Ch2 hw Q14

After an average acceleration of 3.15 m/s2 during 2.47 s, a car reaches a velocity of 16.9 m/s. Find the car's initial velocity.

Ch2 hw Q15

A squirrel runs along an overhead telephone wire that stretches from the top of one pole to the next. It is initially at position 𝑥i=3.79 m, as measured from the center of the wire segment. It then undergoes a displacement of Δ𝑥=−6.17 m . What is the squirrel's final position 𝑥f?

Ch2 hw Q16

Jack and Jill exercise in a 25.0 m long swimming pool. Jack swims 9 lengths of the pool in 153.5 s (2 min and 33.5 s), whereas Jill, the faster swimmer, covers 10 lengths in the same time interval. Find the average velocity and average speed of each swimmer.

Ch2 hw Q17

A person is initially driving a car east down a straight road. The magnitude of the instantaneous acceleration is decreasing with time, but the direction of the acceleration is always to the east. The speed of the car is increasing. decreasing. increasing but then decreasing. decreasing but then increasing. constant.

Ch2 hw Q19

A car starts from rest and reaches a maximum speed of 36.0 m/s in a time of 13.0 s. Calculate the magnitude of the car's average acceleration aavg

Ch2 hw Q2

The froghopper, a tiny insect, is a remarkable jumper. Suppose a colony of the little critters is raised on Rhea, a moon of Saturn, where the acceleration due to gravity is only 0.264 m/s2, whereas gravity on Earth is 𝑔=9.81 m/s2. If on Earth a froghopper's maximum jump height is ℎ and its maximum horizontal jump range is 𝑅, what would its maximum jump height and range be on Rhea in terms of ℎ and 𝑅? Assume the froghopper's takeoff velocity is the same on Rhea and Earth.

Ch3 hw 13

A cannon is mounted on a tower above a wide, level field. The barrel of the cannon is 20 m above the ground below. A cannonball is fired horizontally with an initial speed of 600 m/s. About how far from the base of the tower will the cannonball land?

Ch3 hw Q10 pt 2

A cannon is mounted on a tower above a wide, level field. The barrel of the cannon is 20 m above the ground below. A cannonball is fired horizontally with an initial speed of 600 m/s. Assuming air resistance can be neglected, approximately how long will the cannonball be in flight before it hits the ground?

Ch3 hw Q10 pt1

A projectile is fired over level ground with an initial speed of 𝑣0=381.0 m/s, at an angle of 𝜃=64.2° with respect to the horizontal. Which equation would be most useful for calculating the horizontal range 𝑅 that the projectile will travel?

Ch3 hw Q11

Two projectiles are launched from the ground simultaneously with an initial velocity 4.00 m/s. The first projectile is sent off at an angle of 31∘ with respect to the horizontal, and the second projectile at an angle of 59∘. Which projectile lands on the ground in a region between 1.3 m and 1.5 m from the launcher?

Ch3 hw Q12

A cyclist rides around a flat, circular track at constant speed. Is the cyclist's acceleration vector zero? No, because the direction of the cyclist's velocity vector changes constantly. Yes, because the cyclist rides at constant speed around the track. Yes, because the cyclist's average velocity is zero during each complete circuit. No, because the cyclist's acceleration vector has a non‑zero outward component.

Ch3 hw Q2

Bob has just finished climbing a sheer cliff above a level beach and wants to figure out how high he climbed. All he has to use is a baseball, a stopwatch, and a friend on the ground below with a long measuring tape. Bob is a pitcher and knows that the fastest he can throw the ball is about 𝑣0=32.5 m/s. Bob starts the stopwatch as he throws the ball, with no way to measure the ball's initial trajectory, and watches carefully. The ball rises and then falls, and after 𝑡1=0.510 s the ball is once again level with Bob. Bob cannot see well enough to time when the ball hits the ground. Bob's friend then measures that the ball hit the ground 𝑥=127 m from the base of the cliff. How high above the beach was the ball when it was thrown?

Ch3 hw Q8

A car of mass 𝑚push=1100 kg is capable of a maximum acceleration of 6.50 m/s2. If this car is required to push a stalled car of mass 𝑚stall=1650 kg, what is the maximum magnitude of the acceleration 𝑎 of the two‑car system?

Ch4 hw 11

Two blocks of mass 𝑀1 and 𝑀2 are connected by a massless string that passes over a massless pulley as shown in the figure. 𝑀1 has a mass of 8.75 kg and rests on an incline of 𝜃1=59.5∘. 𝑀2 rests on an incline of 𝜃2=31.5∘. Find the mass of block 𝑀2 so that the system is in equilibrium (i.e., not accelerating). All surfaces are frictionless.

Ch4 hw 12

A person whose mass is 𝑚=98.5 kg steps on a mechanical bathroom scale placed on an inclined plane that makes the angle 𝛼=31.9∘ with the horizontal. What is the reading on the scale?

Ch4 hw 13

A 28.9 kg mass (𝑚) is suspended by the cable assembly as shown in the figure. The cables have no mass of their own. The cable to the left (𝑇1) of the mass makes an angle of 0.00∘with the horizontal, and the cable to the right (𝑇2) makes an angle (𝜃2) of 40.6∘. If the mass is at rest, what is the tension in each of the cables, 𝑇1 and 𝑇2? The acceleration due to gravity is 𝑔=9.81 m/s2.

Ch4 hw 14

Two forces act on an object. The first force has a magnitude of 17.0 N and is oriented 48.0° counterclockwise from the +𝑥‑axis, whereas the second force has 𝑥‑ and 𝑦‑components (−19.0 N,10.5 N). Express the magnitude and direction of the net force.

Ch4 hw 15

Suppose that the maximum power delivered by a car's engine results in a force of 14000 N on the car by the road. In the absence of any other forces, what is the maximum acceleration 𝑎 this engine can produce in a 1350-kg car?

Ch4 hw 19

A bluefin tuna has a mass of 230 kg. Determine the weight 𝑤 of the bluefin tuna.

Ch4 hw 2

Select the option that best completes the statement: In the absence of a net force, an object can be It is not possible to know without more information. accelerating. at rest or in motion with a constant velocity. in motion with a constant velocity. at rest.

Ch4 hw 3

An astronaut has a mass of 75.0 kg. What would be the astronaut's weight 𝑤V on Venus where surface gravity is 90.5% of that on Earth?

Ch4 hw 4

What is the net external force ∑𝐹⃗ext on an apple that weighs 2.5 N when you hold it at rest in your hand?

Ch4 hw 5

In the absence of a net force, an object cannot be moving with an acceleration of zero. accelerating. in motion with a constant velocity. experiencing opposite but equal forces. at rest.

Ch4 hw 8

According to Newton's second law of motion, when a net force acts on an object, the acceleration is inversely proportional to the net force. independent of mass. zero. inversely proportional to the object's mass. directly proportional to the object's mass.

Ch4 hw q 10

A desperate hiker has to think fast to help his friend who has fallen below him. Quickly, he ties a rope to a rock of mass 𝑚r=3.90×102 kg and makes his way over the ledge (see the figure). If the coefficient of static friction between the rock and the ground is 𝜇s=0.348, and the mass of the hiker is 𝑚h=73.3 kg, what is the maximum mass of the friend 𝑚f that the rock can hold so the hikers can then make their way up over the ledge? Assume the rope is parallel to the ground and the point where the rope passes over the ledge is frictionless.

Ch5 hw 1

A block of mass m with a given initial speed slides down a rough incline with constant speed. If a similar block that has a mass of 4m were placed on the same incline with the same initial speed, it would accelerate down the incline with an acceleration significantly less than that of the smaller block. accelerate down the incline with an acceleration significantly greater than that of the smaller block. slide down at constant speed. slowly slide down the incline and then stop. not move.

Ch5 hw 3

If you push a box across a horizontal floor towards the north, in which direction will friction act? north south east west

Ch5 hw 4 pt 1

If the frictional force is 21.0 N and you push the box with a positive force of 29.0 N, what will the net force be? −8.0 N 8.0 N 50.0 N 29.0 N

Ch5 hw 4 pt2

Albert pushes a 12 kg box across a level floor. He pushes with a force of 45 N and observes that the box accelerates in the direction of his push at a rate of 2 m/s2 . Assuming that Albert's push and the friction with the floor are the only horizontal forces acting, what is the magnitude of the frictional force pushing backward on the box? 45 N 120 N 69 N 21 N 24 N

Ch5 hw 5 pt 2

A 2.03 kg book is placed on a flat desk. Suppose the coefficient of static friction between the book and the desk is 0.422 and the coefficient of kinetic friction is 0.229. How much force is needed to begin moving the book?

Ch5 hw 6 pt 1

A 2.03 kg book is placed on a flat desk. Suppose the coefficient of static friction between the book and the desk is 0.422 and the coefficient of kinetic friction is 0.229. How much force is needed to keep the book moving at constant speed once it begins moving?

Ch5 hw 6 pt 2

A 6.510 kg block of wood rests on a steel desk. The coefficient of static friction between the block and the desk is 𝜇s=0.505 and the coefficient of kinetic friction is 𝜇k=0.305. At time 𝑡=0, a force 𝐹=19.8 N is applied horizontally to the block. State the force of friction applied to the block by the table at times 𝑡=0 and 𝑡>0.

Ch5 hw 7 pt 1

A 6.510 kg block of wood rests on a steel desk. The coefficient of static friction between the block and the desk is 𝜇s=0.505 and the coefficient of kinetic friction is 𝜇k=0.305. At time 𝑡=0, a force 𝐹=19.8 N is applied horizontally to the block. State the force of friction applied to the block by the table at times 𝑡=0 and 𝑡>0. Consider the same situation, but this time the external force 𝐹 is 40.0 N. Again, state the force of friction acting on the block at times 𝑡=0 and 𝑡>0.

Ch5 hw 7 pt2

Kayla, a fitness trainer, develops an exercise that involves pulling a heavy crate across a rough surface. The exercise involves using a rope to pull a crate of mass 𝑀=45.0 kgalong a carpeted track. Using her physics expertise, Kayla determines that the coefficients of kinetic and static friction between the crate and the carpet are 𝜇k=0.410 and 𝜇s=0.730, respectively. Kayla uses one of her employees, Ramon, to test the exercise. If the rope makes an angle of 𝜃=25.0∘ with the floor, what is the minimum force 𝐹min that Ramon must apply to set the crate in motion? Use 𝑔=9.80 m/s2.

Ch5 hw Q2 pt1

Kayla, a fitness trainer, develops an exercise that involves pulling a heavy crate across a rough surface. The exercise involves using a rope to pull a crate of mass 𝑀=45.0 kgalong a carpeted track. Using her physics expertise, Kayla determines that the coefficients of kinetic and static friction between the crate and the carpet are 𝜇k=0.410 and 𝜇s=0.730, respectively. Next, Kayla has Ramon pull on the rope as hard as he can. If he pulls with a force of 𝐹=305 N along the direction of the rope, and the rope makes the same angle of 𝜃=25.0∘ with the floor, what is the acceleration 𝑎 of the box?

Ch5 hw Q2 pt2

If the box has a mass of 2.0 kg, what will its acceleration be? (need to figure out frictional force in past example) 0.25 m/s 225 m/s 2−4.0 m/s 24.0 m/s2

Ch5 hw4 pt3 frictional force is 8.0N

Three clowns move a 345 kg crate 11.5 m to the right across a smooth floor. Take the positive horizontal and vertical directions to be right and up, respectively. Moe pushes to the right with a force of 475 N, Larry pushes to the left with 225 N, and Curly pushes straight down with 485 N. Calculate the work 𝑊 done by each of the clowns. Assume friction is negligible.

Ch6 hw 1

Calculate the final speed 𝑣𝑓 of a 2.00-kg object that is pushed for 28.0 m by a 30.0‑N force directed 30.0∘ below the horizontal on a level, frictionless floor, as shown in the figure. Assume the object starts from rest.

Ch6 hw 10

A 1260-kg car moves at 25.0 m/s. How much work 𝑊net must be done on the car to increase its speed to 31.0 m/s?

Ch6 hw 11

An object attached to the free end of a horizontal spring of constant 350 N/m is pulled from a position 14 cm beyond equilibrium to a position 18 cm beyond equilibrium. Calculate the work 𝑊 that the spring does on the object.

Ch6 hw 12

Coil springs are widely used in industry. Those used in scientific instruments must be manufactured to exhibit consistent performance. One important property of a spring is its force constant. The quality control manager of a coil spring manufacturer is examining a coil spring made by her company that compresses 0.0460 m when a mass of 195 kg is placed on it. Calculate the force constant 𝑘

Ch6 hw 14

A spring with a spring constant of 𝑘=85 N/m is stretched a distance of Δ𝑥=0.25 m from its relaxed position. By how much does the spring's potential energy 𝑈k change?

Ch6 hw 15

A gold coin (33.5 g) is dropped from a floor of the Burj Khalifa building, 490 m above ground level. In the absence of air resistance, how fast 𝑣 would it be moving when it hit the ground?

Ch6 hw 17

An 𝑚=12.0 kg block is released from rest on a frictionless incline that makes an angle of 𝜃=36.0∘, as shown in the figure. Below the block is a spring that has a spring constant of 1.45×104 N/m. The block momentarily stops when it compresses the spring by 5.50 cm. How far 𝐿 does the block move down the incline from its release point to the stopping point? Answer in units of centimeters.

Ch6 hw 18

Over 630 m in height, the Burj Khalifa is the world's tallest skyscraper. What is the change Δ𝑈grav in the gravitational potential energy of a $20 gold coin (33.5 g) when it is carried from ground level to a floor of the Burj Khalifa that is 590 m high? Neglect any slight variations in the acceleration due to gravity.

Ch6 hw 19

In the 2016 Olympic games, Deng Wei set a women's record of 147 kg in the clean and jerk. Suppose that she lifted 137 kg during practice. How much work 𝑊 did she do on the weights to lift them above her head, a distance of approximately 1.60 m? For simplicity, assume that she lifted the weights at constant speed.

Ch6 hw 2

An external force 𝐹⃗ moves a 2.50-kg box at a constant speed 𝑣 up a frictionless ramp, as shown in the figure. The force acts in a direction parallel to the ramp. Calculate the work 𝑊 done on the box by this force as it is pushed up the 5.00-m ramp to a height ℎ=3.00 m.

Ch6 hw 20

One of the fastest elevators in the world is found in the Taipei 101 building. It ascends at 16.83 m/s and rises 382.2 m. Each elevator has a maximum load capacity of 1600 kg. What power 𝑃 is required to raise a load of 1210 kg from the lowest level to the top floor?

Ch6 hw 22

You push a 20.0-kg crate at constant velocity up a ramp inclined at an angle of 𝜃=35.0∘ to the horizontal. The coefficient of kinetic friction between the ramp and the crate, 𝜇k, is equal to 0.200. How much work 𝑊 must you do to push the crate a distance of 2.00 m?

Ch6 hw 5

What is the energy 𝐸 required to accelerate a 1665 kg car from rest to 21 m/s?

Ch6 hw 7 pt 1

What is the energy 𝐸 required to accelerate a 1665 kg car from rest to 21 m/s? Compared to the amount of energy required to accelerate a car from rest to 21 m/s, how much energy is required to accelerate the car from 21 m/s to twice that speed, 42 m/s? three times as much twice as much the same four times as much

Ch6 hw 7 pt2

A book slides across a level, carpeted floor with an initial speed of 4.25 m/s and comes to rest after 3.25 m. Calculate the coefficient of kinetic friction 𝜇 between the book and the carpet. Assume the only forces acting on the book are friction, weight, and the normal force.

Ch6 hw 8

A force of 1.100×103 N pushes a man on a bicycle forward. Air resistance pushes against him with a force of 775 N. If he starts from rest and is on a level road, what speed 𝑣 will he be going after 30.0 m? The mass of the bicyclist and his bicycle is 90.0 kg.

Ch6 hw 9

A 70.0 kg ice hockey goalie, originally at rest, has a 0.110 kg hockey puck slapped at him at a velocity of 37.5 m/s. Suppose the goalie and the puck have an elastic collision, and the puck is reflected back in the direction from which it came. What would the final velocities 𝑣goalie and 𝑣puck of the goalie and the puck, respectively, be in this case? Assume that the collision is completely elastic

Ch8 hw 11

A truck has a mass of 800 kg. If the truck is brought to a complete stop, what is the magnitude of the impulse that must be imparted to it?

Ch8 hw 14 pt 1

A truck has a mass of 800 kg. If the velocity of the truck is 20 m/s, what is its momentum?

Ch8 hw 14 pt 2, if needed momentum=16000

A truck has a mass of 800 kg. If it takes 8 s to bring the truck to a stop, what is the magnitude of the force required to stop it?

Ch8 hw 14 pt3, if needed momentum and magnitude=16000 both

Coming to the bottom of a mountain, a skier moving with speed 𝑣 collides with a barrier and is brought to a stop in an amount of time 𝑡. Over the course of the impact, the skier experienced an average net force 𝐹 from the barrier. If the skier's initial velocity had been the same (𝑣) but the time of impact to come to a full stop had been half as long (𝑡/2), what would have been the average net force exerted on the skier during the collision? The average net force would have been 𝐹/4 𝐹 2𝐹 4𝐹 𝐹/2

Ch8 hw 15 pt 1

Coming to the bottom of a mountain, a skier moving with speed 𝑣 collides with a barrier and is brought to a stop in an amount of time 𝑡. Over the course of the impact, the skier experienced an average net force 𝐹 from the barrier. If the time of impact to come to a full stop had been the same (𝑡) but the skier's initial velocity had been four times as much (4𝑣),what would have been the average net force exerted on the skier during the collision? The average net force would have been F/4 F 2F 4F F/2

Ch8 hw 15 pt2

During a neighborhood baseball game in a vacant lot, a particularly wild hit sends a 147 g baseball crashing through the pane of a second‑floor window in a nearby building. The ball strikes the glass at 11.9 m/s, shatters the glass as it passes through, and leaves the window at 8.79 m/s with no change of direction. Calculate the magnitude of this impulse, a positive number

Ch8 hw 17

A 2012.00 lb car is moving at 22.00 miles per hour. Calculate the magnitude of its momentum 𝑝 in SI units.

Ch8 hw 2

What is the momentum of a garbage truck that is 13500 kg and is moving at 10.0 m/s ?

Ch8 hw 3 pt 1

What is the momentum of a garbage truck that is 13500 kg and is moving at 10.0 m/s ? At what speed would a 9.35 kg trash can have the same momentum as the truck?

Ch8 hw 3 pt 2

A wet lump of clay and a bouncy rubber ball, both of mass 𝑚, are thrown at a wall. Both strike the wall at speed 𝑣, but although the ball bounces off with no loss of speed, the clay sticks. What are the changes in momentum of the clay and ball, respectively? 𝑚𝑣; 𝑚𝑣 𝑚𝑣; 2𝑚𝑣 𝑚𝑣; 0 0; 𝑚𝑣 0; 2𝑚𝑣

Ch8 hw 4

21.0 kg shopping cart is moving with a velocity of 8.0 m/s. It strikes a 9.0 kg box that is initially at rest. They stick together and continue moving at a new velocity. Assume that friction is negligible. What was the momentum of the shopping cart before the collision?

Ch8 hw 8 pt 1

21.0 kg shopping cart is moving with a velocity of 8.0 m/s. It strikes a 9.0 kg box that is initially at rest. They stick together and continue moving at a new velocity. Assume that friction is negligible. What was the momentum of the box before the collision?

Ch8 hw 8 pt2

A 21.0 kg shopping cart is moving with a velocity of 8.0 m/s. It strikes a 9.0 kg box that is initially at rest. They stick together and continue moving at a new velocity. Assume that friction is negligible. What is the velocity of the combined shopping cart-box wreckage after the collision?

Ch8 hw 8 pt3

A 1425 kg truck driving at 13.0 m/s collides elastically with a stationary 1175 kg car. If the car is traveling 14.25 m/s just after the collision, what is the velocity of the truck immediately after the collision? Assume that this is a perfectly elastic collision. Round your answer to the hundredths place.

Ch8 hw 9

Select the situation for which the torque is the smallest A 500 kg piece of bronze is placed at the end of a 1 m tree branch A 40 kg piece of chalk is placed at the end of a 12.5 m construction crane arm. The torque is the same for all cases A 8 kg pumice stone is placed at the end of a 62.5 m thin titanium rod. The torque is the same for two cases.

Ch9 hw 10

Which of the statements is true regarding a thin rod that has zero net torque acting on it? The angular acceleration may or may not be zero. There must be no torques acting on the system. The angular acceleration must be zero. There must be two or more torques acting on the system. There can be only one torque acting on the system.

Ch9 hw 11

A 127 kg horizontal platform is a uniform disk of radius 1.73 m and can rotate about the vertical axis through its center. A 68.1 kg person stands on the platform at a distance of 1.09 m from the center, and a 25.5 kg dog sits on the platform near the person 1.31 m from the center. Find the moment of inertia of this system, consisting of the platform and its population, with respect to the axis.

Ch9 hw 12

The triceps muscle in the back of the upper arm extends the forearm. This muscle in a professional boxer exerts a force of 2327 N with an effective perpendicular lever arm of 3.45 cm, producing an angular acceleration of the forearm of 120.0 rad / s2. What is the moment of inertia of the boxer's forearm?

Ch9 hw 13

A car driving around a circular track has a centripetal acceleration of 99 m/s^2 until it hits a slick spot and slides straight off the track If the radius of the track is 21m what is the car's velocity when it leaves the track?

Ch9 hw 2

An optical disk drive in a computer can spin a disk at up to 10,000 rpm. If a particular disk is spun at 3930 rpm while it is being read, and then is allowed to come to rest over 0.502 s, what is the magnitude of the average angular acceleration of the disk? If the disk is 12.0 cm in diameter, what is the magnitude of the tangential linear acceleration of a point 1/11 of the way out from the center of the disk?

Ch9 hw 4

A wheel with radius 44.5 cm rotates 4.09 times every second. Find the period of this motion. What is the tangential speed of a wad of chewing gum stuck to the rim of the wheel?

Ch9 hw 8

A wheel with a tire mounted on it rotates at the constant rate of 3.45 revolutions per second. A tack is stuck in the tire at a distance of 31.1 cm from the rotation axis. What is the tack's tangential speed 𝑣. What is the tack's radial acceleration 𝑎r?

Ch9 hw 9

An engine flywheel initially rotates counterclockwise at 6.91 rotations/s. Then, during 21.1 s, its rotation rate changes to 2.95 rotations/s clockwise. Find the flywheel's average angular acceleration (including its sign) in radians per second squared. Define counterclockwise rotation as positive.

Ch9 hw5

What is the angular speed 𝜔, in rad/s, of an object that completes 8.00 rev every 16.0 s?

Ch9 hw7

What are the components when 𝐴=3.00 and the vector makes an angle 𝜃2=120∘ with respect to the positive 𝑥-axis?

Vectors homework Q4 pt 2

What are the components when 𝐴=3.00 and the vector makes an angle 𝜃3=30.0∘ with respect to the negative 𝑥-axis?

Vectors homework Q4 pt 3

What are the components 𝐴𝑥 and 𝐴𝑦 of vector 𝐴⃗ when 𝐴=8.00 and the vector makes an angle 𝜃1=30.0∘ with respect to the positive 𝑥-axis?

Vectors homework Q4 pt1

Find the magnitude of vector 𝐴⃗ and the angle 𝜃A it makes with respect to the positive 𝑥-axis, measured counterclockwise, when 𝐴𝑥=2.00 and 𝐴𝑦=−4.00.

Vectors homework Q5 pt 1

Find the magnitude of vector 𝐵⃗ and the angle 𝜃B it makes with respect to the positive 𝑥-axis, measured counterclockwise, when 𝐵𝑥=−2.00 and 𝐵𝑦=2.00.

Vectors homework Q5 pt 2

A pinball bounced around its machine before resting between two bumpers. Before the ball came to rest, its displacement was recorded as a series of vectors. All the angles are measured counterclockwise from the horizontal 𝑥‑axis. 𝑉⃗1:83.0 cm at 90.0∘ 𝑉⃗2:55.0 cm at 145∘ 𝑉⃗3:61.0 cm at 223∘ Find the magnitude and direction of the ball's total displacement.

Vectors homework Q6

Find the magnitude of vector 𝐶⃗ and the angle 𝜃C it makes with respect to the positive 𝑥-axis, measured counterclockwise, when 𝐶𝑥=0.00 and 𝐶𝑦=−4.00.

Vectors homework Q6 pt 3

Given the vector 𝐴⃗ with components 𝐴𝑥=4.00 and 𝐴𝑦=12.0, the vector 𝐵⃗ with components 𝐵𝑥=4.00 and 𝐵𝑦=−4.00, and the vector 𝐷⃗=𝐴⃗−𝐵⃗, - calculate the magnitude D of the vector D - Determine the angle theta that the vector D makes with respect to the positive x-axis

Vectors homework Q7

𝐴⃗ is 75.0 m long at a 18.0∘ angle with respect to the +𝑥-axis. 𝐵⃗ is 47.0 m long at a 69.0∘ angle above the −𝑥-axis. What is the magnitude of the sum of vectors 𝐴⃗ and 𝐵⃗? What angle theta does the sum of vectors A and B make with the x-axis?

Vectors hw Q8

As Lucy pushes a box across the floor, she exerts a force on the box in the forward direction. What is the "equal and opposite force" in this interaction, according to Newton's third law? the force of Lucy pushing backward on the floor the force of the box pushing backward on Lucy the force of the floor pushing backward on the box the force of the box pushing forward on the floor

ch4 hw 17

Albert pushes a 12 kg box across a level floor. He pushes with a force of 45 N and observes that the box accelerates in the direction of his push at a rate of 2 m/s2 . What is the net force acting on the box? 24 N 6 N 33 N 12 N 45 N

ch5 hw 5 pt 1