Monday

January 16, 2017
**Physics**

A row of seats is parallel to a stage at a distance of 8.70 m from it. At the center and front of the stage is a diffraction horn loudspeaker that has a width of 7.50 cm. The speaker is playing a tone at a frequency of 9600 Hz . The speed of sound is 344 m/s. a. What is the ...

*Friday, December 9, 2016 by J*

**physics**

A golfer tees off and hits a golf ball at a speed of 31 m/s and at an angle of 35 degrees. What is the horizontal velocity component of the ball? Round the answer to the nearest tenth of a m/s.

*Friday, December 9, 2016 by Anonymous*

**work and energy PHYSICS**

A particle is projected vertically upwards from a point O on horizontal ground which reaches the maximum height Q. What is the energy associated at O and Q?

*Friday, December 9, 2016 by greeshma*

**Physics**

What is the work done when a force of 30Newtons moves through a distance of 20Meters?

*Thursday, December 8, 2016 by Prisca*

**Physics**

The kiloton, which is used to measure the energy released in an atomic explosion, is equal to 4.2 âœ• 1012 J (approximately the energy released in the explosion of 1000 tons of TNT). Recalling that 1 kilocalorie of energy raises the temperature of 1 kg of water...

*Thursday, December 8, 2016 by Bona*

**Physics**

The drawing shows a collision between two pucks on an air-hockey table. Puck A has a mass of 1.5 kg and is moving along the x axis with a velocity of +5.5 m/s. It makes a collision with puck B, which has a mass of 3.2 kg and is initially at rest. The collision is not head-on. ...

*Thursday, December 8, 2016 by Matt*

**Physics**

A space station, in the form of a wheel 197 m in diameter, rotates to provide an â€œartificial gravityâ€ of 2.5 m/s2 for persons who walk around on the inner wall of the outer rim. The rate of the wheelâ€™s rotation in ...

*Thursday, December 8, 2016 by William*

**Physics - studying for finals**

(a) Write the expression for y as a function of x and t in SI units for a sinusoidal wave traveling along a rope in the negative x direction with the following characteristics: A = 5.00 cm, Î» = 75.0 cm, f = 5.00 Hz, and y(0, t) = 0 at t = 0. (Use the following as ...

*Thursday, December 8, 2016 by Jack*

**Physics - studying for finals**

(a) Write the expression for y as a function of x and t in SI units for a sinusoidal wave traveling along a rope in the negative x direction with the following characteristics: A = 5.00 cm, Î» = 75.0 cm, f = 5.00 Hz, and y(0, t) = 0 at t = 0. (Use the following as ...

*Thursday, December 8, 2016 by Jack*

**physics**

A 3.4 kg plant hangs from the bracket shown in the figure. The bracket has a mass of 0.65 kg , and its center of mass lies 9.0 cm from the wall. A single screw holds the bracket to the wall. Find the horizontal tension force in the screw. Hint: Imagine that the bracket is ...

*Thursday, December 8, 2016 by phoebe*

**physics**

the terminal velocity of a tennis ball is about 21 m/s. a tennis ball is dropped from a hot air balloon. how fast will it be moving after falling for 10 s? 21m/s, 77m/s, 9.8m/s, or 98m/s.

*Thursday, December 8, 2016 by candy*

**Physics**

Not sure where to begin with this question--any help appreciated! Two kids sitting on opposite sides of a small lake use sticks to beat the surface of the water at a frequency f=1.5 Hz. They notice that a standing wave pattern develops between the points where they are ...

*Thursday, December 8, 2016 by Jamie*

**Physics**

If the torque required to loosen a nut that is holding a flat tire in place on a car has a magnitude of 31 N Â· m, what minimum force must be exerted by the mechanic at the end of a 24 cm-long wrench to loosen the nut? Answer in units of N

*Thursday, December 8, 2016 by Eric Melendez*

**physics **

experiencing a constant horizontal 1.10 m/s wind, a hot air balloon ascends from the launch site at a constant vertical speed of 2.70 m/s. at a height of 202 m, the balloonist maintains constant altitude for 10.3 s before releasing a small sandbag. how far from the launch site...

*Thursday, December 8, 2016 by jerry*

**Physics**

How many kilograms of water can be evaporated at 100 degrees Celsius by the combustion of 470 litres of fuel oil whose heat of combustion is 37 MJ/Litre

*Thursday, December 8, 2016 by David*

**PHYSICS**

A child (25 kg) walks along a 4 m plank of uniform density (m=8kg) that is laying with one end extending 1 m off the end of a dock. 1. Where is the ceanter of mass located in the plank? 2. What is the magnitude of the torque of the plank about the edge of the dock? 3. How far ...

*Thursday, December 8, 2016 by LESTER*

**Physics**

You exert a force of 200 N at an angle of 15 degrees above horizontal to pull a 10 kg box across the floor at constant velocity. If the coefficient of kinetic friction between the box and the floor is 0.42, what is the acceleration of the box?

*Thursday, December 8, 2016 by Allie*

**Science physics**

How would the voltage output be affected if the armature is made to spin faster?

*Thursday, December 8, 2016 by Anonymous*

**physics**

A 1.6-kg block is attached to the end of a 2.0-m string to form a pendulum. The pendulum is released from rest when the string is horizontal. At the lowest point of its swing when it is moving horizontally, the block is hit by a 10-g bullet moving horizontally in the opposite ...

*Thursday, December 8, 2016 by gillian*

**Physics**

If 32s is required for an object to reach maximum height, what will be the time for an object to come back to its initial position? is it 32sec or -32 sec since it's traveling downwards???

*Thursday, December 8, 2016 by Anonymous 22*

**Physics**

In projectile motion the acceleration at the highest point of curved motion is___. a. 0 b. g c. undefined d. â€“g Which is true about an object was dropped from a 5 storey building? a. initial velocity is zero b. acceleration is equal to â€“g c...

*Thursday, December 8, 2016 by Anonymous 22*

**Physics**

How long does a car with an acceleration of 2.0 m/s2 take to go from 10 m/s to 30 m/s a. 3 m b. 6 m c. 18 m d. 36 m

*Thursday, December 8, 2016 by Karen*

**physics**

how much work is done if a force of 12N moves an object a distance of 5m

*Thursday, December 8, 2016 by princess*

**Physics**

consider the circuit in the figure. find the current in the 13 ohm resistor. Answer in units of A

*Wednesday, December 7, 2016 by Sara*

**Physics **

A child of mass 30 kg stands beside a circular platform of mass 95 kg and radius 2.4 m spinning at 2.3 rad/s. Treat the platform as a disk. The child steps on the rim. a) What is the new angular speed? b) She then walks to the center and stay there. What is the angular ...

*Wednesday, December 7, 2016 by Ana*

**physics**

A half-cup of ice cream contains about 200 food Calories. How much power can be produced if the energy in a cup of ice cream is expended over a period of 10 minutes (600 seconds)? Each food Calorie is equal to 4,184 joules. Write your answer in watts and then in horsepower

*Wednesday, December 7, 2016 by juan*

**Physics**

Tarzan swings on a 33.0 m long vine initially inclined at an angle of 31.0â—¦ with the vertical. The acceleration of gravity if 9.81 m/s What is his speed at the bottom of the swing if he a) starts from rest? Answer in units of m/s b) pushes off with a speed ...

*Wednesday, December 7, 2016 by Jessica*

**Physics**

Please help! 1) While skiing in Jackson, Wyoming, your friend Ben (of mass 73.8 kg) started his descent down the bunny run, 23.9 m above the bottom of the run. If he started at rest and converted all of his gravitational potential energy into kinetic energy, what is Benâ...

*Wednesday, December 7, 2016 by Mikayla*

**Physics**

I am really struggling with these two questions. Please help! 1)Two ice skaters approach each other at right angles. Skater A has a mass of 61.2 kg and travels in the +x direction at 2.25 m/s. Skater B has a mass of 66.2 kg and is moving in the +y direction at 1.3 m/s. They ...

*Wednesday, December 7, 2016 by Mikayla*

**Physics**

A circular disk of mass 0.4 kg and radius 36 cm, initially not rotating, slips down a thin spindle onto a turntable (disk) of mass 1.7 kg and the same radius, rotating freely at 3.4 a) Find the new angular velocity of the combination; b) The change in the kinetic energy? c) If...

*Wednesday, December 7, 2016 by Ana*

**Physics**

A 100 watts light bulb has an average life of 2000 hours. How much energy does it consume over its lifetime? The only thing I got was power=100 watts and time = 2000 hours but I need to convert to seconds and I don't kn how to do that.

*Wednesday, December 7, 2016 by Salma*

**Physics**

You exert a horizontal force of 200 N to pull a 10-kg box across the floor. If the coefficient of kinetic friction between the box and the floor is .42, what is the acceleration of the box?

*Wednesday, December 7, 2016 by Anonymous*

**Physics**

We have a heat engine that produces 150 J of heat, does 40 J of work, and emits 110 J into another system. What is the efficiency of the heat engine? (show you work)

*Wednesday, December 7, 2016 by Mark*

**physics**

A hoop is at rest at the top of a 3.0 m long ramp with an angle of evelation of 24Â°. If the hoop rolls down the ramp, what is the final velocity of the hoop at the bottom of the ramp

*Wednesday, December 7, 2016 by jordan*

**Physics**

A 775 kg roller coaster car is at the top of a roller coaster car is at the top of a roller coaster as shown below. The height of the car at point A is the minimum height that is necessary for the car to stay on the loop. The radius of the loop is 30 m. What is the height of ...

*Wednesday, December 7, 2016 by jordan*

**physics**

A 873-kg (1930-lb) dragster, starting from rest completes a 403.6-m (0.2523-mile) run in 4.935 s. If the car had a constant acceleration, what would be its acceleration and final velocity?

*Wednesday, December 7, 2016 by Jahlyssa*

**Physics**

How much heat energy is needed to change 0.25kg of water at 100Â°C to steam at 100Â°C? Show your work. Please don't give me the answer, I just need help figuring out how to find the answer. Thanks!

*Wednesday, December 7, 2016 by Mark*

**Physics**

Chameleons catch insects with their tongues, which they can extend to great lengths at great speeds. A chameleon is aiming for an insect at a distance of 22 cm. The insect will sense the attack and move away 60 ms after it begins. In the first 60 ms, the chameleonâ€...

*Wednesday, December 7, 2016 by Anonymous*

**Physics**

To what potential a sphere of radius 10cm be charged so that the surface density of charge is equal to 1

*Wednesday, December 7, 2016 by Arisha imtiaz*

**Physics**

How much heat does a freezer need to remove from 1kg of water at 40Â°C to make ice at 0Â°C? (You will need to use the specific heat of water to drop the temperature first, before trying to make the phase change!) Show your work. Please help! Also, this site...

*Wednesday, December 7, 2016 by Jay*

**Physics**

How much heat energy is needed to change 0.25kg of water at 100Â°C to steam at 100Â°C? Show your work. Please don't give me the answer, I just need help figuring out how to find the answer. Thanks!

*Wednesday, December 7, 2016 by Mark*

**Physics**

The heat of fusion for water is 3.3 x 105 J/kg. How much heat energy is needed to can 3kg of ice at 0Â°C to water at 0Â°C? Show your work. Help please!! Don't give the answer, but please help me find the answer?! Thanks

*Wednesday, December 7, 2016 by Emily*

**Physics**

Just as no mechanical device can be 100% efficient, no heat engine can transfer 100% of its heat to a single object. Some of the heat energy must be wasted (released into the environment). We have a heat engine that produces 150 J of heat, does 40 J of work, and emits 110 J ...

*Wednesday, December 7, 2016 by Jessica*

**physics**

Is the photoelectric effect a direct consequence of the wave character of E.M radiation or of the particle character of E.M radiation?

*Wednesday, December 7, 2016 by JAY*

**PHYSICS**

Particles called mesons are produced by accelerator beams. if these particles travel at 2.70* 10^8 m/s and live 2.60*10^-8 s when at rest relative to an observee how long do they live as viewed in the laboratory?

*Wednesday, December 7, 2016 by JAY*

**Physics**

A mango is dropped and falls freely from rest what are its position and velocity after 1.0s,2.0s, and 3.0s

*Wednesday, December 7, 2016 by Aliyu lawan danzomo*

**physics**

How much work is done in lifting a 300 Newton rock 10 meters from the ground?

*Wednesday, December 7, 2016 by battang*

**physics**

What is the time constant of a 10 H inductor and a 200 ohm resistor connected in series? Is my work correct? I did: T= L/R = 10 H divided by 200 ohm = 0.05 seconds = 50 milliseconds mS. Is that correct?

*Tuesday, December 6, 2016 by Brett*

**Physics**

A bungee jumper runs off a platform and falls 40m before his bungee cord begins to stretch. Once the bungee cord begins to stretch his velocity slows by 20 m/s in 12m. If the mass of the bungee jumper is 55kg, what is the average force the bungee applies on him?

*Tuesday, December 6, 2016 by A*

**Physics**

A 100 watts light bulb has an average life of 2000 hours. How much energy does it consume over its lifetime? The only thing I got was power=100 watts and time = 2000 hours but I need to convert to seconds and I don't kn how to do that.

*Tuesday, December 6, 2016 by Salma*

**Physics!!!!!!**

A 0.18 kg baseball moving at +26 m/s is slowed to a stop by a catcher who exerts a constant force of âˆ’360 N. a) How long does it take this force to stop the ball? b) How far does the ball travel before stop- ping?

*Tuesday, December 6, 2016 by Anonymous*

**physics**

In the circuit we have E=48V, R=6 ohm and L=4H. We close the switch at the instant t=0, the current I in the circuit grows from zero to its maximum value Io, and the permanent phase is established. A) determine the value of Io. B) calculate the values of the potential ...

*Tuesday, December 6, 2016 by vicky*

**physics**

The self induced e.m.f created in a coil has the value of 24mV at the instant when the current is 4A and varies at the rate of 10A/s. What is the value of the self magnetic flux kn the coil at this instant?

*Tuesday, December 6, 2016 by vicky*

**physics**

if copper rod has a length of 2m at 30 Â°C. what is its length at 70 Â°C ?

*Tuesday, December 6, 2016 by alia*

**physics**

the speed of sound in air at 0Â°C is 330m/s. at what temperature will the velocity of sound become 366m/s ?

*Tuesday, December 6, 2016 by alia*

**physics**

A wooden box, with a mass of 22 kg, is pulled at a constant speed with a rope that makes an angle of 25Â° with the wooden floor. What is the tension in the rope?

*Tuesday, December 6, 2016 by adam*

**Physics**

Your 2000 kg car is going 40 m/s on the highway when you see a police car up ahead. You apply the maximum 10000 N of brake force to slow your car down to the speed limit of 30 m/s. How many seconds will it take you to get down to the speed limit?

*Tuesday, December 6, 2016 by Rebecca*

**physics**

A Syringe is filled with a solution of viscosity n=1.75x10^-3 pa s. The plunger of syringe has cross sectional area 9 x 10^-5 m^2. The needle has length 30mm and internal radius 3 x 10^-4 m. Intravenous pressure in patient is 2.0 kPa. What force must be applied to plunger of ...

*Tuesday, December 6, 2016 by Hannah*

**physics**

An electron beam is accelerated through 50kv potential difference and then passes through magnetic field produced by coils for 1cm the screen is located 10 cm from end is 50 cm wide.when the field is turned off the beam stikes the centre of screen.what field strength is ...

*Tuesday, December 6, 2016 by Anonymous*

**Physics**

Hi, do you know how angular velocity relates to a "tight spiral" in football?

*Monday, December 5, 2016 by Donna *

**physics **

A wire of length 60cm and mass 10kg is suspended by a pair of flexible leads in a magnetic field magnitude and direction of the current required to remove the tension in the supporting leads.

*Monday, December 5, 2016 by Mztura *

**physics**

A tuning fork is set into vibration above a vertical open tube filled with water. The water level is allowed to drop slowly. As it does so, the air in the tube above the water level is heard to resonate with the tuning fork when the distance from the tube opening to the water...

*Monday, December 5, 2016 by kassy *

**physics**

An organ pipe is 81 cm long and at a temperature of 20 degrees C. What is the fundamental (in Hertz) if the pipe is closed at one end?

*Monday, December 5, 2016 by kassy *

**physics**

A hiker determines the length of a lake by listening for the echo of her shout reflected by a cliff at the far end of the lake. She hears the echo 2.20 s after shouting. How long (in meters) is the lake?

*Monday, December 5, 2016 by kassy *

**physics **

A guitar string is 97 cm long and has a mass of 3.6 g. The length L from the bridge to the support post is 61 cm, and the string is under a tension of 570 N. What is the frequency of the fundamental tone?

*Monday, December 5, 2016 by kassy *

**physics**

A rope of mass 0.73 kg is stretched between two supports 31 m apart. If the tension in the rope is 1100.0 N, how long (in seconds) will it take a pulse to travel from one support to the other?

*Monday, December 5, 2016 by kassy *

**General Physics II**

Hi, this is about thin film interference in ray optics. My book presents two similar problems, but somehow uses different paths for the same variable. I'll list out the given variables: --Problem A-- n1 < nf > n2, delta phase is therefore lambda over two. Film ...

*Monday, December 5, 2016 by Justin*

**Physics**

A 55.0 kg diver steps off a diving board and drops straight down into the water. The water provides an upward average net force 1480 N. If the diver comes to rest 5.6 m below the water's surface, what is the total distance between the diving board and the diver's ...

*Monday, December 5, 2016 by Julia*

**Physics**

We have a heat engine that produces 150 J of heat, does 40 J of work, and emits 110 J into another system. What is the efficiency of the heat engine? Please don't give me the answer! Just help figure out how to find it! The description for the lesson with this question was...

*Monday, December 5, 2016 by Leila*

**Physics **

ou build a loop-the-loop in your backyard. It has a diameter of 3.10 m. a) How fast will you have to be moving at the top of the loop to avoid falling off? b)If you'll be coasting from the time you get to the bottom of the loop, how fast will you have to be going at the ...

*Monday, December 5, 2016 by Mary*

**Physics**

Two identical racing horses go around a semicircular turn in a racecourse. The horses have the same speed, but horse A is on the inner side while horse B is on the outer side of the circular turn. Which horse has the greater acceleration while in the turn?

*Monday, December 5, 2016 by Bloop*

**Science Physics**

I don't understand how I would know what would happen if it collided or bounced, etc. How do I solve a question like this? Suppose the total momentum of two masses before collision is 100kg m/s. What is the total momentum of the two masses after they collide? 0 kg m/s 50 k...

*Monday, December 5, 2016 by Jake*

**Physics **

Kate (m = 50 kg) is swinging on a tire tied by a (light) rope (L = 3 m) to a tree limb. Her twin Ashley comes along and squeezes into the tire with her. Assume that at all times the centre of mass of the person(s) riding the tire is at the end of the rope. a) What was the ...

*Sunday, December 4, 2016 by Anonymous *

**Physics **

A mass (0.5 kg) and spring (k = 250 N/m) system oscillates with an amplitude of 3.5 cm. a) What is the total mechanical energy of the system? b) What is the maximum speed of the mass? c) What is the maximum acceleration of the mass? I need help please. What equation should I ...

*Sunday, December 4, 2016 by Anonymous *

**Physics **

A 0.5 kg air-track car is attached to the end of a horizontal spring of constant k = 20 N/m. The car is displaced 15 cm from its equilibrium point and released. a) What is the car's maximum speed? b) What is the car's maximum acceleration? c) What is the frequency f of...

*Sunday, December 4, 2016 by Anonymous *

**Physics**

A 200kg wagon is pushed along a horizontal surface at a constant 10m/s when it is released. After rolling a distance of 45m the wagon comes to a complete stop. Find the coefficient of friction.

*Sunday, December 4, 2016 by Emma *

**Physics**

A 15 kg box is given an initial push to start it moving up a frictionless ramp with angle theta = 30 degree and length delta r = 22m. What horizontal force F will keep the box moving with constant speed to the top of the ramp?

*Sunday, December 4, 2016 by Mary*

**Physics**

A ball having a weight of 1.5 N is dropped from a height of 4 meters. (Neglect air friction.) How much mechanical energy is "lost" just before it hits the ground?

*Sunday, December 4, 2016 by Noah Alvarado*

**Physics!!!!!!**

In a scene in an action movie, a stunt man jumps from the top of one building to the top of another building 5.0 m away. After a running start, he leaps at an angle of 10â—¦ with respect to the flat roof while traveling at a speed of 5.6 m/s. The acceleration...

*Sunday, December 4, 2016 by Anonymous*

**Physics**

(a) If the wavelength of an electron is 5.37 âœ• 10âˆ’7 m, how fast is it moving? (b) If the electron has a speed equal to 3.80 âœ• 106 m/s, what is its wavelength? What equation should I use?

*Sunday, December 4, 2016 by Jake*

**physics**

A daredevil is shot out of a cannon at 49.7â—¦ to the horizontal with an initial speed of 29.9 m/s. A net is positioned at a horizontal dis- tance of 49.8 m from the cannon from which the daredevil is shot. The acceleration of gravity is 9.81 m/s2 . At what ...

*Sunday, December 4, 2016 by Kacie*

**physics**

In a scene in an action movie, a stunt man jumps from the top of one building to the top of another building 4.4 m away. After a unning start, he leaps at an angle of 17â—¦ with respect to the flat roof while traveling at a speed of 4.3 m/s. The acceleration ...

*Sunday, December 4, 2016 by Kacie*

**physics**

A force is applied to a 3 kg mass and produces 5 m/s 2 acceleration. What acceleration would be produced by the same force applied to a 12.2 kg mass? Answer in units of m/s 2 .

*Sunday, December 4, 2016 by jorge*

**PHYSICS HELP**

Two identical gas cylinders each contain 20.0 kg of compresses air at 1.00 x 106 pa and 275 K. One of the cylinders if fitted with a safety valve that releases air into the atmosphere if and only if the pressure in the cylinders raises above 1.10 x106 pa (the other cylinder ...

*Sunday, December 4, 2016 by David*

**physics (urgent)**

Two identical gas cylinders each contain 20.0 kg of compresses air at 1.00 x 106 pa and 275 K. One of the cylinders if fitted with a safety valve that releases air into the atmosphere if and only if the pressure in the cylinders raises above 1.10 x106 pa (the other cylinder ...

*Sunday, December 4, 2016 by David*

**Physics**

A 52.4 kg pole vaulter running at 10.8 m/s vaults over the bar. The acceleration of gravity is 9.81 m/s2 . If the vaulterâ€™s horizontal component of ve- locity over the bar is 0.60 m/s and air resis- tance is disregarded, how high is the jump? Answer in units ...

*Sunday, December 4, 2016 by Anonymous*

**PHYSICS (REALLY DIFFICULT PLEASE HELP)**

At a temperature of 18.0Â°C of 23.0cm^3 of a certain gas occupies has pressure of 103 kPa. (a) What volume would the gas occupy at a temperature of 0.00Â°C and pressure of 101kPa? (b) 1.00 moles of a certain gas occupies a volume of 22.4 litres at 0.00&...

*Sunday, December 4, 2016 by Josh*

**Physics**

In a scene in an action movie, a stunt man jumps from the top of one building to the top of another building 5.0 m away. After a running start, he leaps at an angle of 10â—¦ with respect to the flat roof while traveling at a speed of 5.6 m/s. The acceleration...

*Sunday, December 4, 2016 by Anonymous*

**Physics**

A daredevil is shot out of a cannon at 44.9â—¦ to the horizontal with an initial speed of 27.5 m/s. A net is positioned at a horizontal dis- tance of 41.2 m from the cannon from which the daredevil is shot. The acceleration of gravity is 9.81 m/s2 . At what ...

*Sunday, December 4, 2016 by Anonymous*

**physics 2**

How much higher will mercury stand in the open arm in a J-Tube manometer, if air column in the closed arm is reduced to 4 cm, the mercury id at the same level in both open and closed arms when the air column in the closed arm is 15 cm long. Assume barometric pressure, 1 atm.

*Sunday, December 4, 2016 by prince*

**physics**

A 2000-kg automobile with four-wheel drive and weight distributed equally on the four 60-cm diameter wheels can accelerate from 0 to 27 m/s (60 MPH) in 6 seconds. a. Calculate the minimum coefficient of static friction between the tires and the ground. (10 pts.) b. What torque...

*Sunday, December 4, 2016 by jennifer*

**Physics **

A car of weight 1.4*10^4N is moving up an incline at a constant speed of 6.2 m/s . The incline makes an angle of 5.0 to the horizontal. A frictional force of 600 N acts on the car in opposite direction. State the net force of the car

*Sunday, December 4, 2016 by Ashlin*

**physics**

Determine the force per meter on a lightning bolt at the equator that carries 20 000 A and is perpendicular to the Earthâ€™s magnetic field, 3x10-5 T. What is the direction of the force if the current is straight up and the Earthâ€™s field ...

*Sunday, December 4, 2016 by ainul*

**Physics**

Santa Claus (mass = 150 kg) is leaning his sled(mass = 50 kg, length = 6 m) at an angle of 72Â° against the wall of the house to enter from the roof the living room. Considering a coefficient of friction of 0.29 between the ground and the sled and no friction between...

*Sunday, December 4, 2016 by Chika*

**Physics**

Material X has a coefficient of linear expansion a = 0.00000271/degree C. What value would you expect its volume coefficient of expansion to be

*Saturday, December 3, 2016 by Mary*

**Physics**

A baseball is thrown at an angle of 20â—¦ relative to the ground at a speed of 25.8 m/s. The ball is caught 43.6152 m from the thrower. The acceleration due to gravity is 9.81 m/s2 .

*Saturday, December 3, 2016 by Anonymous*

**Physics**

If a ball is rolling down an inclined ramp straight, will the change in position be squared for every passing second or would it just be multiplied by two? I'm not sure if this makes sense so here's what I mean in an example for the change in position will be squared ...

*Saturday, December 3, 2016 by Alison*

**Physics**

To a cyclist riding west at 20 kg/hr, the rain appears to meet him at an angle of 45Â° with the vertical. When he rides at 12 km/hr, the rain meets him at an angle of 19Â°48â€™ with the vertical. What is the actual direction of the rain?

*Saturday, December 3, 2016 by Gul*

**Physics**

Not at all sure where to start with this problem. Any help would be appreciated! The siren of an ambulance has a frequency f=500 Hz. A pedestrian standing on a sidewalk listens to this siren as the ambulance passes by at a speed of 65 mph. The speed of sound in air is 330 m/s...

*Saturday, December 3, 2016 by Jamie*

**Physics**

A 30 kg child sits in a swing supported by two chains, each 1.4 m long. (a) If the tension in each chain at the lowest point is 265 N, find the childâ€™s speed at the lowest point. (Neglect the mass of the seat.) Answer in units of m/s. (b) Find the force of ...

*Saturday, December 3, 2016 by alicia*