# physics please HELP !

128,894 results, page 30

### Spanish

translate this to english please but do not use google tanslate because it is not accurate they don't give you good enough answers please help me as soon as possible thank you so much ms. sue! el parque nacional

### History please help!

Who were the first four caliphs? A)rulers who had a personal connection to Muhammad. B) a group of wealthy traders C) five gods D) missionaries to Africa I pick A. Please help!

### physics-rotational dynamics

Two astronauts, each having a mass of 75.0 kg, are connected by a 10.0 m rope of negligible mass. THey are isolated in space,orbiting their center of mass at speeds of 5.00 m/s. calculate A)magnitude of the angular momentum of the system by treating astronauts as particles and...

### Physics

Help with Physics homework Please and thank you!? I need help on these two questions. I'm not looking for the answer because I really need to learn how to do this on my own. But if someone could show me what equations to use to answer the steps in the questions and explain to ...

### physics

The x-component of vector A is -25.0 m and the y-component is +40.0 m. a) what is the magnitude of vector A? b) What is the angle between the direction of vector A and the positive direction of vector x? can you please help me with the steps to accomplishing these?

### Physics

What is the weight of an object whose mass is 50 slugs? What is the mass of an object whose weight is 50 lbs.? Please indicate formula used.

### Chemistry(Please help)

What is the pH of a 5.06E-2 M aqueous solution of sodium acetate? I know that I would set this up the same way I did for the previous question that I posted. I am just confused on how to find the Ka. I know it is kw/kb but for what compound is what I do not know. Chemistry(...

### english

Please help me with my thesis. i have to write a thesis statement in the topic topic "Poverty in USA". like i had lots but my teacher didn't agree with those. can anyone please give me idea what to write. by starting the sentence with " Poverty in USA ....." please give me ...

### physics

an unstretched hanging spring is 50cm long. suspending a 100N weight from it makes its lenght 60cm. Adding another 100N weight will make the spring -- 60cm, 70 cm, 80 cm, 100 cm, or 120 cm. No idea how they came up with any of the five ??? My answer was different! Please help!

### Physics

What is the probability density at the fifth carbon atom if the electron is in the n=2 energy level? I have the formula as follows: Probability density = p5= (2/1.65) sin^2 (4x2pi/11) I know the final answer is 0.69 nm -1. However, I do not know how to retrieve this final ...

### Physics. Please Help!!!

A hot air balloon starts at its launching station and it goes at a horizontal speed of 2.7 m/s and a vertical wind of 1.1 m/s. Once it reaches an altitude of 202 m, it stays at that altitude for 10.3 s, which is when it drops a sandbag. How far will the sandbag land from the ...

### Physics. Please Help!!

A hot air balloon starts at its launching station and it goes at a horizontal speed of 2.7 m/s and a vertical wind of 1.1 m/s. Once it reaches an altitude of 202 m, it stays at that altitude for 10.3 s, which is when it drops a sandbag. How far will the sandbag land from the ...

### Physics-Gravitation

What is the gravitational potential energy of a two-particle system with masses 5.4 kg and 5.0 kg, if they are separated by 1.3 m? If you triple the separation between the particles, how much work is done (b) by the gravitational force between the particles and (c) by you? ...

### Physics

While an elevator of mass 2681 kg moves upward, the tension in the cable is 29.4 kN. (a) What is the acceleration of the elevator? (b) If at some point in the motion the velocity of the elevator is 1.04 m/s upward, what is the elevator's velocity 3.96 s later? Please helppp ...

### physics. HELP PLEASE !

An athlete executing a long jump leaves the ground at a 28.0 angle and lands 7.60m away. part a)What was the takeoff speed? part b) If this speed were increased by just 8.0 % , how much longer would the jump be? i got for part a)9.48 m/s but i need help with part b

### Physics(Please help)

1) A force vector has a magnitude of 579 newtons and points at an angle 43o of below the positive x axis. Find the x scalar component and the y scalar component of the vector? For the x component I did 579cos(43) = 423.45 N. Is this correct? For the y component I did 579sin(43...

### Physics- PLEASE HELP

Two pipes of equal length are each open at one end. Each has a fundamental frequency of 715 Hz at 300 K. In one pipe the air temperature is increased to 313 K. If the two pipes are sounded together, what beat frequency results?

### Physics

Photons of energy 12eV are incident on a metal. It is found that current flows from the metal until a stopping potential of 8.0V is applied. If the wavelength of the incident photons is doubled, what is the maximum kinetic energy of the ejected electrons? What is KEmax in eV. ...

### AP PHYSICS

An owl has good night vision because its eyes can detect a light intensity as small as 5.0*10^-13W/M^2. What is the minimum number of photons per second that an owl eye can detect if its pupil has a diameter of 8.5nn and the light has a wavelength of 510nm? Can anyone please ...

### Physics help again!

A ball is thrown horizontally off a 35 m tall building. It hits the ground 80 m from the bottom of the tower. a. what is the balls time in the air [i got 2.67] b. what is its initial velocity? [i got 0] c. What is the magnitude and direction of its velocity as it strikes the ...

### Physics, Collisions

A pendulum of a given mass is pulled back through a given vertical height and released to swing back down to a 'wall' where it impacts. Can i use mg delta h to get E kin; and then use E= half mv^2 to get the collision impact velocity? Would someone check my thinking please? ...

### Physics

For beginner parachutists, the terminal velocity must be less than 5.00 m/s, and the parachutes used have a k-value that is normally distributed with a mean of 2.05/s and a standard deviation of 0.04/s. If the acceleration due to gravity is 9.81 m/s^2, determine the ...

### PHYSICS

2 pool balls of equal mass experience a perfectly elastic head on collision. 1 ball is traveling at 2m/s and the other at 3m/s in the opposite direction.What is thier speed just after impact? I know the balls swap speed and change direction but can't find the correct formula ...

### physics

A car is sitting at the top of an inclined plane, which is 5.2 meters long and meets the horizontal at an angle of 12 degrees. The cart is then allowed to roll to the bottom of the incline. What will be the velocity of the cart at the bottom of the incline. (4.61m/s) Please ...

### physics

Consider the following set of equations, where s, s0 and r have units of length, t has units of time, v has units of velocity, g and a have units of acceleration. Take k to be dimensionless.Identify if these are dimensionally correct or incorrect. 1)v^2= 2as + kav 2)s = s0 + ...

### Physics

An 80-ft-diameter Ferris wheel rotates once every 23s. What is the apparent weight of a 80kg passenger at the lowest point of the circle? Express your answer in SI units. I know to use the equation mg-N=m(v^(2)/r) but I can't figure out how to come away with the apparent ...

### Physics

A cricket ball rotates at 1800 rev/min as it travels through the space in a straight line at 160 km/hr. How many times does it revolve after traveling 20m? Can someone confirm with me if 13.5 revolutions in 20m is right. That's the answer i got too. If it's wrong can someone ...

### physics

PLEASE HELP! When Babe Ruth hit a homer over the 10 m -high right-field fence 80 m from home plate, roughly what was the minimum speed of the ball when it left the bat? Assume the ball was hit 1.2 m above the ground and its path initially made a 39 ∘ angle with the ground.

### Physics

Ive tried numerous methods, but I cant seem to get this right. Please help, and explain step by step. An object's position is given by x=bt+ct^3, where b=1.50m/s and c=0.640m/s3. To study the limiting process leading to the instantaneous velocity, calculate the object's ...

### Physics (Please Help)

At the He-Ne laser wavelength (L= 632.8 nm) the refractive indices of crystal quartz are n o = 1.54264 and n e = 1.55171 calculated from its Sellmeier equation. The laser is incident from the air onto the surface of crystal quartz at an angle of incidence of 45 degrees. For ...

### physics PLEASE HELP

A source emits sound uniformly in all directions. There are no reflections of the sound. At a distance r1 from the source the sound is 6.5 dB louder than it is at a distance r2 from the source. What is the ratio r1/r2?

### physics

a +35x10^-6 C point charge is placed 32 cm from an identical +32x10^-6 C charge. how much work would be required to move a +50.0x10^-6 C test charge from a point midway between them to a point 12 cm closer to either of the charges? please show work.

### Physics

True/False 1)Specular reflection obeys the laws of reflection while diffuse reflection does not. False. drwls said its true but I disagree can you please explain. 2)A convex lens is used to obtain an enlarged virtual image. True.

### physics

a ray of light strikes a rough surface such that the angle of incidence is 40.0. what is the angle of reflection 1. 0 degrees 2. 20.0 degrees 3. 40.0 degrees 4. the angle of reflection cannot be determined. I am confused between 3 and 4 but I think the correct answer is 40.0 ...

### PHYSICS

Could u help with physics hw! i keep trying but i keep getting the wrong answer? a 71g autographed baseball slides off of a 1.3 m high table and strikes the floor a horizontal distance of .83m away from the table. 1.how fast was it rolling on the table before it fell off? ok ...

### math

On the first day he runs 1.5 km. Every day he runs 10% more than the day befor. a) Write down the distance he runs on the second day of training. ..... 1,5km +0,15 = 1,65 km b) Calculate the total distance He runs in the first seven days of training. When I counted my answer ...

### Physics Help!!!! Please check

A 3.00 kHz tone is being produced by a speaker with a diameter of 0.150 m. The air temperature changes from 0 to 29°C. Assuming air to be an ideal gas, find the change in the diffraction angle . Please tell me where I am going wrong. first I converted the temp to kelvin 0 = ...

### Physics

One of the most powerful cranes in the world, operating in Switzerland, can slowly raise a load of 6000 tonne to a height of 12 m. (1 tonne = 1000 kg) The acceleration of gravity is 9.81 m/s2 . How much work is done by the crane? Answer in units of MJ I found it by using Work...

### Physics

Could someone please explain how you get this answer??? A skier with a mass of 60.0 kg pushes off with a horizontal speed of 3.0 m/s from the top of a snow covered hill. As he slides down the hill, his height decreases by 42 m over a distance of 100 m of travel. How much will ...

### Physics

Calculate the change in momentum in each of the following situations and state the direction of the change in momentum. a) A 4kg bowling ball strikes a stationary pin head-on at a speed of 3m/s. It continues to move in its original direction, but its speed is reduced to 2m/s. ...

### Physics

Calculate the change in momentum in each of the following situations and state the direction of the change in momentum. a) A 4kg bowling ball strikes a stationary pin head-on at a speed of 3m/s. It continues to move in its original direction, but its speed is reduced to 2m/s. ...

### Physics

I agree with this and see were it comes from net force = (delta p)/t so momentum is conserved when net force equals zero... net force = (delta p)/t 0 = (delta p)/t however the following is not true 0 = (delta p)/t = P - Po were p is momentum and Po is used to indicate inital ...

### PHYSICS

A mass is thrown upwards with an initial velocity of 30m/s. A second mass is dropped from directly above, a height of 60m from the first mass 0.50s later. When do the masses meet and how hight is the point where they meet? I NEED TO KNOW HOW TO SHOW THIS IN A STEP BY STEP ...

### Physics

The frequency of circular motion for a charged particle moving around in the presence of a uniform magnetic field does not depend on ... a)The radius of the circle b)The mass of the particle c) The charge of the particle d) The magnitude of the magnetic field e) Actually, it ...

### PHYSICS- please help! i cant get my last problem

The compound eyes of bees and other insects are highly sensitive to light in the ultraviolet portion of the spectrum, specifically light with wavelengths between 300.0 nm and 400.0 nm. To what frequencies do these wavelengths correspond? (Assume that the speed of light to be 3...

### Physics

A shopper in a supermarket pushes a cart with a force of 35 N directed at an angle of 52(angle sign here) downward from the horizontal. Find the work done by the shopper on the cart as the shopper moves along a 50.0 m length of aisle. Someone tell me if this is right: W= (35....

### Physics-Please help with formula

If you were in a rotor style ride and the riders accelerate until the speed of ride is reached- if the radius of the cylinder is 5.0m and the coefficient of friction between clothes and wall is 0.5, how do you find minimum speed you would need to stick to the wall of the ride...

### physics

two ends of a train moving with constant acceleration pass a certain point with velocities u and v. what is the velocity with which the middle point of the train passes the same point? I have asked this question before you have answered u+v/2. but my mam says it is (u^2+v^2/2...

### Physics

For the first part of this question I got 12.12m/s B. With the help of a friend the boy measures the height to which the ball returns and finds it to be 5.2 meters. How fast was the ball moving when it left the ground? I wrote this down mass of ball: 0.40kg height if house: 7....

### physics

Two pieces of metal (A and B) are identical in every way, except that A has a much larger thermal expansion coefficient. If equal amounts of heat are added to both pieces of metal, which metal does more work on its surroundings? 1. A 2. B 3. They do the same work. 4. Unable to...

### physics

A bicyclist wants to make it from one building to the next. The first building he is standing on is 20 m tall. The building he wants to reach is 12 m tall. He is moving at 4 m/s and the gap between both buildings is 5 m. Will he make it? Please just show me how to break down ...

### physics please help

a 65 kg bag is dragged along a 12m ramp in order to get from the ground to the floor of the loading dock 2m above the ground. determine the efficiency of of the ramp. The frictional force acting on the bag is 50N due to the ramp. I don't understand how to the find the energy ...

### Math/physics

This is my last problem. Please help! A motorcycle rider starts out on top of a ramp 10 m high and then rides down and jumps the motorcycle when he comes to the end of the ramp (like evil knivel). The rider is at the peak of his jump at 5 m. How fast is the motorcycle going ...

### 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 1 ...

### physics

A car moving with a constant speed of 83 km/h enters a circular, flat curve with a radius of curvature of 0.40 km. If the friction between the road and the car’s tires can support a centripetal acceleration of 1.25 m/s2, without slipping, does the car navigate the curve ...

### Physics(Please check)

A rectangular plate is rotating with a constant angular speed about an axis that passes perpendicularly through one corner, as the drawing shows. The centripetal acceleration measured at corner A is n times as great as that measured at corner B. What is the ratio L1/L2 of the ...

### physics urgent please help!

way safety engineers build soft barriers so that cars hitting them will slow down at a safe rate. A person wearing a safety belt can withstand an acceleration of 300 m/s 2 . How thick should barriers be to safely stop a car that hits the barriers at 81.7 km/h? Answer in units ...

### English

Posted by rfvv on Thursday, December 16, 2010 at 3:40pm. Posted by rfvv on Thursday, December 16, 2010 at 3:21am. {At a restaursant} For hear or to go? Is this for here or to go? It's for here, please. It is to go, please. (Are the expressions above all grammatical? What is ...

### math help

Thank you for helping me with the last problem Reiny and Bosnian. However, I have one more problem that I need help with please and I have no idea how work the problem. I used an on line calculator to get the answer. It didn't give an explanation on how to do the problem ...

### physics

Suppose the amount of heat removed when 3.0kg of water freezes at 0 degree C were removed from ethyl alcohol and its freezing/melting point of -114 degree C. How many kilograms of ethyl alcohol would freeze? PLEASE GIVE ME SOME HINTS!!!THANKS A LOT!!!!

### physics

4.8mF capacitor in series with 500 ohm resistor is connected, via a switch, to a 12V battery. What is the current through the resistor at t=1.0s after the switch is closed? I tried doing I^2R = 1/2 CV^2 and solving for I but the answer wasn't correct. can some1 please help? ...

### physics help

An auto race is held on a circular track. A car completes one lap in a time of 16.9 s, with an average tangential speed of 48.1 m/s. Find the following (a) the average angular speed (b) the radius of the track i found part a which was .3716 but need help with part b please

### physics help

The earth orbits the sun once a year (3.16 10^7 s) in a nearly circular orbit radius 1.50 10^11 m. With respect to the sun, determine the following. (a) the angular speed of the earth 1 rad/s (b) the tangential speed of the earth 2 m/s (c) the magnitude and direction of the ...

### Physics 1

At t = 0, a stone is dropped from a cliff above a lake; 1.3 seconds later another stone is thrown downward from the same point with an initial speed of 33 m/s. Both stones hit the water at the same instant. Find the height of the cliff. No idea how to get the height. Help please!

### Physics

A boy throws a ball straight up into the air so that it leaves his hand at 11 m/s. 1) If the ball has mass 0.15 kg and the boy's arm moved through 1.5 m as he threw the ball, then what average force did he exert on the ball? Please show it step by step along with the equation ...

### Physics

A boy throws a ball straight up into the air so that it leaves his hand at 11 m/s. 1) If the ball has mass 0.15 kg and the boy's arm moved through 1.5 m as he threw the ball, then what average force did he exert on the ball? Please show it step by step along with the equation ...

### Physics

Starting from rest, a 5kg block slides 2.5 m down a rough 30o incline in 2 seconds. Find a) the work done by the force of gravity. b) the work done by friction. c) the work done by the normal force Help ASAP please!! Show work step by step only with the equation

### physics

sorry! trying to get the drawing correct! PLEASE HELP!! I HAVE A TEST TOMORROW!! i just posted this problem but a very important drawing was left out! if Q=30 uC, q=5.0 uC, and d=30cm, what is the magnitude of the electrostatic force on q in N? (Ke= 8.99 x 10^9 Nm^2/C^2) (uC= ...

### Physics please help!!

A man with mass m =96.4 kg (weight = 212.1 lbs is walking towards a patio at 2.00 m/s (4.47 mph) when, at the last moment, he realizes the sliding glass door is closed. He puts out his hand suddenly to stop himself, and comes to a halt in 90.0ms. Find the magnitude of the ...

### Physics

A string is wrapped around a pulley of radius .20m and momentum of inertia .40 kg•m^2. The string is pulled with a force of 28 N. what is the magnitude of the resulting angular acceleration? Can someone please go through the steps or at least guide me through them. I missed ...

### Physics

A string is wrapped around a pulley of radius .20m and momentum of inertia .40 kg•m^2. The string is pulled with a force of 28 N. what is the magnitude of the resulting angular acceleration? Can someone please go through the steps or at least guide me through them. I missed ...

### can someone please help w/ physics?

An object of mass 154 kg moves in a smooth straight tunnel of length 2990 km dug through a chord of a planet of mass 3.19 × 10^24 kg and radius 1 × 10^7 m Find the eﬀective force constant of the harmonic motion. The value of the universal gravitational constant is 6....

### Physics

Please Help I have no idea how to approach this problem In a "Rotor-ride" at a carnival, people rotate in a vertical cylindrically walled "room." If the room radius was 5.7m , and the rotation frequency 0.35 revolutions per second when the floor drops out, what minimum ...

### Physics

I understand that I have to use newtons laws of motion but I don't really get how to aplly them to this problem. Please help. An aircraft with a mass of 11000kg moving at constant speed and altitude is powered by propellers and experiences drag from air. The thrust is 225kN ...

### physics again (check answers please)

What net force increases a velocity of a car from 20 m/s to 35 m/s in 8.0 s if the mass of the car is 1600 kg? (3000 N). What force would cause the car to stop? (3000N) What coefficient of friction is needed to supply the force of friction? (.0191) are they correct?

### physics urgent please asnwer it i m begging u

a metal sample carrying a current along X-axis with density Jx is subjected to a magnetis field Bz(along z-axis). the electric field Ey developed along Y-axis is directly proportional to Jx as well as Bz. the constant of propotionality has SI unit. 1. m²/As 2. m²/A 3.As/m³ ...

### Physics

A concave spherical mirror has a radius of curvature 15 cm. A 1 cm tall bulb is placed in front of the mirror such that its image is formed 10 cm in front of the mirror what is the focal length position of object magnification of object height of object Please help!! I am ...

### physics

if the coeffiecient of friction between a 32kg metal plate and the floor is 0.16, what force is required to roll this metal plate across the floor at a uniform speed? how much work is done if the metal plate is rolled to a distance of 15m? Please response i need your help.

### Physics

A 2.00-kg object is hanging on a 1.1m string. The object is pulled 20cm away from the equilibrium position and held there. a) What is the pulling force in the string when the object is kept still ? b) Now the object is released, what is the speed of the object when it goes ...

### AP Physics

A certain length of wire has a resistance of 21 ohms. This wire is melted down and from the same volume of material a new wire is formed that is three times longer than the original wire. What is the resistance of a new wire? ***PLEASE SHOW ALL WORK!!!

### Math

PLEASE PLEASE HELP ME WITH THESE 2 PROBLEMS STEP BY STEP AND SHOW WORK! z/12=9 what is the value of z show how you found it. 5 x g= 230 what is the value of g show how you found it. PLEASE I REALLY NEED HELP!!!

### PHYSICS PLEASE HELP QUICK

An object with an initial speed of 4.0 meters per second accelerates uniformly at 2.0 meters per second2 in the direction of its motion for a distance of 5.0 meters. What is the final speed of the object? Vi=4m/s a=2.0m/s*s d=5.0m Vf=? Vf©÷=Vi©÷+2ad Vf©÷=(4m/s)©÷+ 2(2m...

### physics

i REALLY don't get this problem. PLEASE HELP!!! the position of a runner during a 3 second time interval the runners position changes from x1 = 50m to x2 = 30.5m what was the runners average velocity? find the average speed as well as the average velocity.

### PHYSICS PLEASE HELP

A satellite has a mass of 5850 kg and is in a circular orbit 4.50 x 10^5 m above the surface of a planet. The period of the orbit is two hours. The radius of the planet is 4.20 x 10^6 m. What is the true weight of the satellite when it is at rest on the planet's surface?

### Physics

A block of aluminum that has dimensions 2.07 cm by 2.55 cm by 5.00 cm is suspended from a spring scale. The density of aluminum is 2702 kg/m^3. (a) What is the weight of the block? 0.699 N (b) What is the scale reading when the block is submerged in oil with a density of 817 ...

### Physics

A heater cansupply 98000J an hour. If a lot of ice is already at 0 degrees, how much ice can be turned to water? check my work please: Q/l=m 98000J/kg / 3.35 * 10^5J = 029kg of ice can be turned to water

### Physics - Rube Goldberg Project

I need to make a Rube Goldberg Machine and it must demonstrate projectile motion, conservation of energy and conservation momentum, any idea on what to make and how to make it? Help please

### Physics-Help Please!

a 25gram bullet is fired upward through a .36kg block. the block goes up 17cm in the air and the bullet goes up 24m into the air. What is the initial velocity of the bullet?

### Physics Please

A boy on a swing is pulled to a position 2.34 m off the ground and released. At the fastest and lowest point of the swing the boy is 0.50 m off the ground and travelling 3 m/s. The percent efficiency of this swing system is?

### Physics

Calculate amount of energy needed to completely vaporize a 50g piece of 20 degree C silver melting point 1064 C L(f) = 64KJ/Kg Boiling point 2856C L(v) = 1645 KJ/Kg c= 0.13KJ/Kg degrees C I'm thinking I balance each side to equal each other but I'm not dure-I've done specific ...

### reading

sentense with 11 elephant Please keep in mind that we don't do students' homework for them. Once you write a sentence, please re-post and someone here will let you know if you're right or need to work on it some more. =)

### pre-cal/trig

PlEASE help me with this!! I need it as soon as possible....... cos(x-(pi/4))+sin(x-(pi/4))=1 Find the answer from 0 to 2pi. When I slove this, I got cosx+sinx=(1/ square root of 2). then I don't know what to do the rest. Please help me.

### Ms. Sue please

Could you please clarify what your intentions were behind what you said on Friday the 24th in a thread that was marked as "society"? The time stamp was 2:22. I have already left my own personal interpretation there.

### PLEASE AND THANK U

i just want to sat that I appreciate all u teachers helping me, but please don't provide one site for me which is Wikipedia. I don't understand a single thing wen I reach that page. It confuses me more, but thanx

### calculus please help

I posted this below but had no response. I would appreciate help with details please.How do I find the indefinite integral of h(u)=sin^2(1/5u) this is one fifth u. Does it involve double angle formulas? Thanks.

### calculus--please helpp

if the line 3x-4y=0 is tangent in the first quadrant to the curve y=x^3+k, find k. all i know is that its related to finding a derivative and i m basically completely lost....can please someone provide me some help?????

### pre-calc HELP PLEASE

solve using identities for all angles (dont use multiple angle method)show work please cuz i am so confused. 2sin2x-3sinx=0

### matt/116

Will someone please help me find the answer to this question please. How do you write a system of linear equations in two variables? Explain this in words and by using mathematical notation in an equation.

### social studies

3 things in history that impacted in south America,europe,asia,africa and austrlia.(please list all and I can do the rest) P.S please get back to me by tomorrow before 2 o' clock