# Homework Help: Science: Physics

## Recent Homework Questions About Physics

**Physics**

The Black Pearl has once again sailed into Port Royal and is firing its guns at the fort. The cannons atop the fort wall have been disabled, but there remains a single cannon at sea level which must defend the town. If the gunner estimates that the ship is 400 meters ...

**PHYSICS**

Why does the lower body rotate in the opposite direction when the upper body is thrown? angular momentum?

**PHYSICS**

A 5 kg block rests on a frictionless horizontal surface. A cord attached to the block passes over the pulley whose diameter is 0.120 m to the hanging block of mass 5 kg. The system is released from rest and the blocks are observed to move 3m in 2.0 s. A. What is the tension in...

**PHYSICS**

A string is wrapped around the rim of a flywheel 0.400 m in radius, and a steady pull of 50.0 N is exerted on the cord. The wheel is mounted in frictionless bearings on a horizontal shaft through it's center. The moment of inertia of the wheel is 4.00 kg.m^2 .Calculate the ...

**physics**

Determine the frequency of the note F4, 5 Seminotes above middle c (C4=261.6Hz) So would it be C4 = 261.6Hz x 1.05946^5 The fact they say semi notes is throwing me off, so I'm not sure if it's right.

**physics**

Red light with a wavelength of 7.0x10^-7 m travels at a speed of c. When it enters glass it's speed is reduced to 2.0x10^8 m/s. Calculate the wavelength of this redlight in glass. Assume that the frequency does not change. I'm really confused and I'm not sure how to do this ...

**Physics**

An air column that is open at both ends is 1.50m long. A specific frequency is heard resonating from the column what is the longest wavelength and it's associated frequency that could be responsible for this resonance? The speed of sound is 345m/s. So what I did is: v=2L = 2*1...

**PHYSICS, help!**

A 5 kg block rests on a frictionless horizontal surface. A cord attached to the block passes over the pulley whose diameter is 0.120 m to the hanging block of mass 5 kg. The system is released from rest and the blocks are observed to move 3m in 2.0 s. A. What is the tension in...

**Physics**

The left face of a biconvex lens has a radius of curvature of magnitude 12.8 cm, and the right face has a radius of curvature of magnitude 17.9 cm. The index of refraction of the glass is 1.45 a) Calculate the focal length of the lens for light incident from the left. b) After...

**Physics**

A roller coaster car is loaded with passengers and has a mass of 500 kg along with a speed of 18 meters/second at the dip. The radius of curvature of the track at the bottom point of the dip is 12 meters (gravity = 9.8 meters/second2). What force is exerted on the roller ...

**Physics help pls**

A spherical bowling ball radius 0.1 m and mass4.0 kg is rolling without slipping to ward the ball rack assume h=0.45m the liners sped at the bottom of the step is 2.85 m/s A find moment of interia of the ball B find the total kinetic energy st the bottom of step C find the ...

**PHYSICS**

A cord can b streated to it elastic limit by 2N.if a 35m of d cord by 0.6 By a force of 0.5n wat wil b d L wendforce2.5n

**physics**

A tennis ball with a velocity of 30.0 m/s to the right is thrown perpendicularly at a wall. After striking the wall, the ball rebounds in the opposite direction with a velocity of -8 m/s to the left. If the ball is in contact with the wall for 0.010 s, what is the average ...

**Physics 11**

A rifle bullet of mass 60g leaves the muzzle of a rifle with a V=5.8*10^2m/s. If the rifle has a mass of 3.1 kg, with what V will it recoil? I'm at a total loss here because I feel like I don't have enough information... I just need to know what formulas to use with the ...

**physics**

A hose contains 20 lamps of 200 W for each lamp and a heater of power 1500 W. they are all connected to supply voltage of 240 volt. Calculate; (a) The total current when all loads operates at the same time. (b) Total energy when 10 lamps and the heater they operate for 5 hours.

**physics 1**

a simple pendulum is 1m long.what is its period?

**physics 1**

what is the peiod of vibrating object which an acceleration of 8.0m/s .when its displacement is 1.0m?what should be the answer?

**physics 1**

a simple pendulum is used to measured the value of g.when the lenght of the pendulum is 98.5cm, the period is measured to be 2s.Find the value of g?

**physics**

A fighter jet is flying at Mach 3.2 in air of temperature 2 degrees C. What is the planes speed? I really don't understand how to do this question. I'd appreciate your help!

**Physics**

A seagull drops a claim from a height of 40m above the rocks. If the air temperature is 0 degrees C, how long after the claim is dropped does the sound of it drinking the rocks directly below reach the seagull? Assume that the seagull hovered in place during the drop.. So what...

**physics 1**

what is the peiod of vibrating object which an acceleration of 8.0m/s .when its displacement is 1.0m?what should be the answer?

**physics**

a destroyer sends out a sonar pulse that returns from a submarine in 1.68s. if the spped of sound in the sea of water is 1531m/s, how far away is the submarine I don't really understand what the question is asking. I appreciate your help! Thank you

**Physics**

10gm of steam 100°c are blown on the surface of 90gm water at 0°c contained in a calorimeter of water 10gm.all steams are condensed .calculate the increase in entropy of the system

**physics**

Does the momentum from the arms transfer to the body if you stop it when jumping? so if you jump vertically and you swing your arms forward to give them an angular momentum and then your arms reaches it's limit. does the angular momentum transfer to the body as a whole causing...

**physics**

Radon 86222Rn is a radioactive gas with a half-life of 3.82 d. If there are initially 400 decays/s in a sample, how many radon nuclei are left after 2 d ? Please help, I don't understand how to do this.

**science (physics)**

A body travels 10m in 5th second and 30m in 10th second. Find its initial velocity and acceleration.

**PHYSICS**

V R 5, L 1.2KG, HEIGHT 10M WORK INPUT 800J FIND THE USEFUL OUTPUT, EFFICIENCY, M A (TAKE G=10M/S )?

**PHYSICS**

A MACHINE HAS A VELOCITY RATIO OF 5 HAS AN EFFICIENCY OF 40.WHAT EFFORT WOULD BE NEEDED TO LIFT A LOAD OF 100N?

**Physics**

A 3-kg mass has a speed of 5.0m/s at the bottom of a 37 degree incline. How far up the incline does the mass slide before it stops if the friction force acting upon its motion is 20N? Thanks.

**Physics/ electricity**

Two charges, separated by a distance of 1.3 m, attract each other with a force of 0.078 N. If one charge is +3.7 μC, what is the other charge?

**Physics**

an earth satellite has an elliptical orbit with an eccentricity value, e=0.40 and on orbital period of 10 hours and 54.0 minutes. Find the height above the surface at its closest approach point.

**physics**

When a guitar string is sounded against a 440Hz note, 12 beats are heard in 2.0s. a) what are the possible frequencies of the string? b) when the same string is sounded against a 435Hz note, 33 beats are heard in 3.0s. What is the frequency of the string? I honestly am very ...

**physics**

how do i find maximum height (meters) and initial velocity (m/s) if i have the time (seconds), horizontal range, and horizontal velocity

**physics**

how do i find the horizontal velocity (m/s) when i have the angle, the time, and horizontal range?

**Physics HELP!**

A locomotive of mass 2.1 x 104 kg travelling at 2.0 m/s runs into an identical stationary locomotive. a) If the collision is perfectly inelastic, what is the speed of the two trains after the collision? b) If the collision is perfectly inelastic, what fraction of the energy is...

**Physics**

A 10.0 kg box is placed on a ramp that is inclined at 30.0 degrees to the horizontal. Determine the force of friction required to keep the block stationary. Determine the minimum coefficient of friction required to keep the box stationary.

**Physics**

A 12.0 kg object is on a surface that is inclined 30 degrees and the coefficient of friction is 0.65. Determine the force of static friction if the block remains stationary.

**Physics**

A 5.0 kg penguin sits on top of a 12 kg sled, as in the figure. A horizontal force of 45 N is applied to the sled, but the penguin keeps himself stationary by holding onto a string attached to the wall. The coefficient of kinetic friction between the penguin and the sled is 0....

**Physics**

On takeoff, the combined action of the engines and the wings of an airplane exert a force of 8.00 x 103 N on the plane upward at an angle of 65.0˚ above the horizontal. The plane rises with constant velocity in the vertical direction while continuing to accelerate in the ...

**Physics**

An 1800 kg helicopter rises with an upward acceleration of 2.0 m/s2. What lifting force is supplied by its rotating blades?

**Physics**

A baseball has a mass of 0.145 kilograms, and a bowling ball has a mass of 6.8 kilograms. What is the gravitational force between them if their centers are 0.5 m apart? 1.0 × 10–13 m 1.3 × 10–10 m 2.6 × 10–10 m 1.1 × 10–8 m

**physics**

a volumetric flask made of pyrex is calibrated at 20°c. if it is filled to 100ml with 35°c acetone. what us the volume of the acetone when it cools to 20°c and how significant is the change in the volume of the flask.

**physics**

A car is moving at 20 m / s before it applies the brakes for 4 s. It slows at a constant rate to 10 m / s. Five seconds after this, the brakes are applied again and stop the car in 5 seconds. The car slows at a constant rate during this period of time as well. What is ...

**Physics**

two basketball players collide player 1 with a mass of 55.0 kg experiences a -15.6 m/s2 acceleration. if the player 2 has a mass of 48.5 kg what acceleration did he experience immediately following the collision?

**11 grade / physics**

find the work by a body which is moving with a velocity of 10m/s and after covering some distance it has the velocity of 20m/s mass of the body 100kg

**Physics**

1. What happens to the stack of books if the applied force exceeds the maximum static frictional force? 2. What is the minimum size for the static frictional force, and under what conditions will the minimum static frictional force be observed? 3. What type of friction acts ...

**physics**

a force of 0.8N stretches an elastic spring by 2cm. find the force constant. f e = k=? f=ke 0.8=0.02 * k k=0.8/0.02 k=40N/m

**Physics**

a 10.0 kg box is placed on a ramp that is inclined at 30.0 degrees to the horizontal. Determine the force friction required to keep the block stationary. Determine the minimum coefficient of friction required to keep the box stationary.

**Physics**

A 12.0 kg object is on a surface that is inclined 30 degrees and the coefficient of friction is 0.65. Determine the force of static friction if the block remains stationary.

**physics**

what is the physics principle behind fiber optics

**Physics**

a charge q1=5.00nc is placed at the origin of an xy-coordinate system ,and a charge q2=-2.00nc is placed on the positive x-axis at x=4.00cm (a.) if a third charge q3=6.00nc is now placed at the point x=4cm, y=3.00cm. find the x and y components of the total force exerted on ...

**Physics-Answer Check**

You have an LED bulb that uses 4 watts of power and gives an output of 170 lumens. The operating voltage is 120 volts. Using this data, find the following. 1. What is the current that the LED bulb uses? Ans. 0.03 ampere 2. What is the effective resistance of this bulb? I'm not...

**Physics-Circuits**

How does a circuit breaker work to protect against an overloaded circuit?

**Physics**

A diver springs upward with an initial speed of 2.93 m/s from a 3.0-m board. (a) Find the velocity with which he strikes the water. [Hint: When the diver reaches the water, his displacement is y = -3.0 m (measured from the board), assuming that the downward direction is chosen...

**physics**

A rescue plane is flying horizontally at a height of 132 m above the ground. The pilot spots a survivor and releases an emergency kit with a parachute. The kit descends at a constant vertical acceleration of -6.89 m/s2 and the initial plane horizontal speed is 68.9 m/s. ...

**physics**

a car moves north with a constant velocity of 50km/hr.how far will it have traveeled in 4hours?the return trip takes 8hours. what is the average speed for the entire trip?

**Physics**

No idea how to do this. All I know is E=hf and found that a is 3.96 x 10^-19 Consider a sidewalk section that has an area of 1 m^2 and assume the sun is directly overhead. Also, assuming the sun is beaming primarily green light, which has a wavelength of 500 nm. (a) What ...

**Physics**

For a I got 36666.67 seconds which I don't know if its right and then b I know my answer is wrong because I got 0.0375 for wavelength.And I don't understand how to do e or f. The Voyager 1 spacecraft is at the edge of the solar system, about 11 billion km away. (a) How ...

**Physics**

When table salt is put in a candle ﬂame, it burns bright yellow because of emission from the sodium atoms. This emission is at 590 nm. (a) What is the natural resonant frequency of the sodium atom that produces this emission (i.e. what is the frequency of this light)? (b...

**Physics**

How fast would you need to be travelling relative to an observer in order for them to see a 15% increase in your mass?

**Physics**

An observer on Earth sees you travel 1000 m at half the speed of light. What distance do you think that you travelled?

**Physics**

If a proton in a proton beam experiences a downward force of 2.0X10-14N while traveling in a magnetic field of 8.3X10-2T west, what is the velocity?

**Physics**

An arrow 2.5cm high is placed at a distance of 25cm from a diverging mirror of focal length 20cm. Find the nature,position and size of the image formed.

**Physics**

The focal length of a concave mirror that produces four times larger real image of an object held at 5cm from the mirror is.....

**Physics**

When table salt is put in a candle ﬂame, it burns bright yellow because of emission from the sodium atoms. This emission is at 590 nm. (a) What is the natural resonant frequency of the sodium atom that produces this emission (i.e. what is the frequency of this light)? (b...

**Physics**

The Voyager 1 spacecraft is at the edge of the solar system, about 11 billion km away. (a) How long does a radio signal from Voyager 1 take to get to the Earth? (b) Its radio works at 8 GHz. What is the wavelength? (c) What type of light is this? (d) What is the energy of...

**physics**

A source delivers an AC voltage of the form Δv = (89.0 V) sin (70πt), where Δv is in volts and t is in seconds, to a capacitor. The maximum current in the circuit is 0.460 A. Find the following. (a) Find the rms voltage of the source. (b) Find the frequency of the source. (...

**physics**

breaks are applied to a car moving with a velocity of 30 km/s . The breaks produce a retardation of 6 m/s^2 . How long will the car take before coming to a stop.

**Physics**

A gas initially occupies 4.5L at 350k and 22kPa. How many moles and molecules are present?

**physics**

A cat walks along a plank with mass M= 7.00 kg. The plank is supported by two sawhorses. The center of mass of the plank is a distance d1= 0.850 m to the left of sawhorse B. When the cat is a distance d2= 1.11 m to the right of sawhorse B, the plank just begins to tip. If the...

**Physics**

Describe the structure of an atom, the quantised shell model and how it produces absorption and emission spectra.

**Physics**

A 95 kg halfback makes a turn on the football field. The halfback sweeps out a path that is a portion of a circle with a radius og 12 meters. The halfback makes a quarter of a turn around the circle in 2.1 seconds. Determine the speed, acceleration and net force acting upon ...

**pls help physics problem**

A 0.230-kg wooden rod is 1.55 m long and pivots at one end. It is held horizontally and then released. 1) What is the angular acceleration of the rod after it is released? three sf with units 2) What is the linear acceleration of a spot on the rod that is 1.02 m from the axis ...

**physics**

When the play button is pressed, a CD accelerates uniformly from rest to 420 rev/min in 5.0 revolutions. Part A If the CD has a radius of 6.5 cm and a mass of 20 g , what is the torque exerted on it? Express your answer using two significant figures. N.m

**physics help**

Example 11-9 depicts the following scenario. A cat walks along a plank with mass M= 7.00 kg. The plank is supported by two sawhorses. The center of mass of the plank is a distance d1= 0.850 m to the left of sawhorse B. When the cat is a distance d2= 1.11 m to the right of ...

**Physics**

A 34.0 kg block accelerates along a frictionless ramp that is inclined at 35 degrees. Determine the acceleration of the block.

**Physics**

A 12.0 kg object is on a surface that is inclined 30 degrees and the coefficient of friction is 0.65. Determine the force of static friction if the block remains stationary.

**Physics**

A plane with a mass of 4.50 x 10^3 kg accelerates on takeoff at 10.0 m/s2. What is the net force acting on the plane?

**Physics**

Two basketball players collide. Player 1, with a mass of 55.0 kg, experience a -15.6 m/s2 acceleration. If player 2 has a mass of 48.5 kg, what acceleration did he experience immediately following the collision?

**Physics special relativity**

The distance from earth to the galactic centre is 23000 ly. What constant speed would be required to make the journey in 30 y of an astronaut's lifetime? I know the answer should be 0.99999915c but don't know how to get there with time dilation or length contraction

**physics**

Someone is blowing over the top of a water bottle creating a noise. If the bottle is 0.3m tall and has 0.1m of water in it, find the following (assume the speed of sound is 340m/s)

**Physics**

An Australian emu is running due north in a straight line at a speed of 13.0 m/s and slows down to a speed of 10.9 m/s in 2.20 s. Assuming that the acceleration of the bird remains the same, how far the bird will travel before it comes to a full stop?

**physics**

A tube that is open on both ends is 4 meters long. Assuming that the speed of sound is 340m/s, find the following: a) What is the wavelength of the fundamental standing wave (the first harmonic) b) What is the frequency of the fundamental wave? c) What is the frequency of the ...

**PHYSICS**

1.How does a flip work? pretend your on a trampoline and jump vertically. How can you jump up in the air and flip.Where is the force coming from to give you a torque? 2.Do you add up linear momentum and rotational momentum for a net momentum? Like energy?

**physics**

1. A bullet has mass 5g. It is fired with a velocity of 50 ms-1 (g=9.8 ms-2) and strikes on a pendulum of mass 5 kg. Find out the height at which the pendulum is raised.

**Physics**

A particle with a charge of -4.5 x 10-5 C, a mass of 2.5 x 10-7 kg, and a velocity of 7.0 x 10-5 m/s [E] is traveling perpendicularly through an external magnetic field such that the force of gravity is balanced by the magnetic force. Determine the direction and magnitude of ...

**Physics**

A charge with a value of 3.0 x 10-5 C is located 2.5 cm from a charge with a value of 6.5 x 10-5 C. Determine the distance from the larger charge to the point where the total electric field is zero.

**Physics**

A 1000 kg rocket without an internal propulsion system is launched with an initial speed of 7.00 x 102 m/s. Determine the maximum height attained by the rocket.

**physics**

A tube that is open on both ends is 4 meters long. Assuming that the speed of sound is 340m/s, find the following: a) What is the wavelength of the fundamental standing wave (the first harmonic) b) What is the frequency of the fundamental wave? c) What is the frequency of the ...

**physics**

A string is vibrated with a wave that has a wavelength of 6 meters. How long is 1 loop of the standing wave?

**physics**

A ship is anchored in a bay. The echo of the ship's foghorn, reflected from an iceberg, is heard 5.0 seconds after the horn is sounded. The temperature of the air is -10.0 degrees Celsius. How many meters away is the iceberg? Show your work.

**physics**

What frequency would a listener hear if a train moves away from the listener at 180 km/hr? The frequency of the horn is 3500 Hz, and the air temperature is 19.0 degrees Celsius. Show work, and include 3 significant figures.

**physics**

You push back and forth on a 5 m high flagpole and make it sway back and forth. When you push it with a frequency of 2 Hz you get it into its fundamental standing wave. a) How fast do the waves travel through the flagpole? b) What frequency would you have to apply to get it ...

**physics**

I need a answer about these? Calculate the net electric force exerted on a particle of charge -4.0mc due to the influence of charge +5.0mc and -3.0mc at distance of 20cm & 80cm, 50cm from it?

**physics**

A constant force acts on a body mass 0.9 kg at rest for 10s.If the body moves a distance of 250m ,the magnitude of the force is

**hello reiny damon steve can you help me physics**

Find the Gravitational potential at a point on the earth's surface. Take mass of earth as 5.98*10^24kg, it's radius as 6.38*10^6m and G=6.67*10^-11Nm^2kg^-2. Plz i need sir damon and steve including reiny to show me step and solution plz

**Physics**

I'm trying to find the relationship between electric field strength and distance from point charge as an equation. I found the equation cd = E/(c*c). c is the factor by which the distance changes and E is the field strength. Is the equation good enough?

**physics**

Suppose a tank contains 714 m3 of neon (Ne) at an absolute pressure of 1.01×10^5 Pa. The temperature is changed from 293.2 to 294.7 K. What is the increase in the internal energy of the neon?

**physics**

a stone is thrown vertically upward with an intial velovity of 12m/s, after some time it returns to the same position a)what is the displacement of the stone b)the highest point it reached if it took 2 seconds for the stone to reach this point c)the kinetic energy of the stone...

**physics**

the rate at which radiant energy from the sun reaches the earth's upper atmosphere is about 1.50kW/m2. the distance from the earth to the sun is 1.50*10^11m, and the radius of the sun is 6.96 * 10^8m. if the sun radiates as an ideal black body (e=1), what is the temperature of...