# Homework Help: Science: Physics

## Recent Homework Questions About Physics

Physics
when tuning a piano, amusician plays a note that should be at 110Hz while at the same time tapping a 110Hz tuning fork and holding it next to the strings. He hears beats at 4Hz. (A) state and explain what frequencies the piano could be producing (b) explain how the musician ...

Physics
3. What happens to the speed of ocean waves as they come close to shore? How can this be explained from what you've learned so far? (this the teacher means what do the lessons have to do with this question) 4. Sound travels faster through wood than through air. Sound also ...

physics
a brass rod is 2m long at a certain temperature. What is its length for a temperature rise of 100k, if the expansivity of brass is 18*10

Physics 1
a skier of mass 70.0kg is pulled up a slope by a motor-driven cable. How much work is required to pull the skier 60.0 m up a 35.0 degree slope (assumed to be frictionless) at a constant speed of 2.0m/s? The Value of g is 9.81 m/s^2?

Physics
the coefficient of kinetic friction between both blocks and the table is .200. determine the accelerations of blocks A and B each of which has a mass of 5.0kg The diagram shows a table with two blocks labeled A and B on them. A is connected to a rope that goes over a pulley ...

Physics
5. If a wave has a wavelength of 20m and a speed of 100 m/s, what is the period of the oscillation? v = wavelength / period 100 = 20 / period 100*20 = periodperiod = 20 / 100 2000 s = period OR period = 20 / 100 period = 0.2 s I don't know which one is correct, please help?!

physics
2)A wave is represented by the equation y =2sin.pi(0.5x - 200t) where all distance are measured in centimeters and time in seconds. For this wave, calculate the : (a) frequency (b) wave length (c) speed (d) amplitude step plz

physics help me plz
A man at the back of a crowd watches a parade by holding a plane mirror just above his head and the parade passes 6m behind his head and the mirror is 0.25m in front of the man. How far does the image appear to be from the man... help i need solution

Physics
Water is falling on turbine at a rate of 6000 kg/min the height of fall is 100 m what is the power given to turbine?

Physics
A brass is 2m long at a certain temperature.what is its length for a temperature rise of 100k if the expansivity of brass is 18×10^6k^1

physics
a woman is draining her fish tank by siphoning the water into an outdoor drain the rectangular tank has footprint area A and depth H . the drain is located a distance D below the surface of the water in the tank , where D>>H . the cross section area of the siphon tube is...

Physics
A bullet of mass 20gm penetrates a board of thickness 10cm and mass 1kg at rest. If the board is free to move,find the thickness to which the bullet will penetrate. I used conservation of momentum to find the combined velocity of bullet and the board in terms of the initial ...

Physics
The focal length of a small concave mirror is 2.5cm in order to use this mirror by dentist .The distance of tooth from mirror is

Physics
The occupants of a car traveling at a speed of 30 m/s note that on a particular part of a road their apparent weight is 15% higher than their weight when driving on a flat road. a. Is that part of the road a hill or a dip? b. What is the vertical curvature of the road? Please ...

Physics
Boxes are moved on a conveyor belt from where they are filled to the packing station 11.3m away. The belt is initially stationary and must finish with zero speed. The most rapid transit is accomplished if the belt accelerates for half the distance, then decelerates for the ...

Fun Physics
A box is given a push up a 16.1° incline. When it reaches the bottom again it is only going 0.59 its original speed. Find the coefficient of kinetic friction. *I know the answer is .06 but I don't know how!

Physics
Calculate the pressure due to water experienced by a diver working 25m below the surface of water in dam.(density of water is 1g/cm3 and g=10N/kg.

Physics
A man can row a boat at a speed of 2metres per second . The man set out to row the boat in a river from A to B. The water in the river flows 0.8metres per second in the opposite direction.Determine the velocity of the boat through the water.

physics
a body is allowed to slide down a frictionless track from rest under gravity . The track end in a circular loop of diameter D . What should be the minimum height of the body in terms of D so that the body successfully complete the loop.

physics
a stone is dropped down a well if it takes 5s to reach the surface of the water calculate how deep the well is , what is the velocity when it reaches the surface of the water

physics
A body of mass 10 kg is moving with uniform velocity 20m/sec. Calculate its velocity if it enters in a black hole?

In an examination of certain number of candidates 18 passed mathematics, 17 passed physics, 11 passed both mathematics and physics, 1 failed both subjects. Find the number of candidates that passed. i. Mathematics only. ii. Physics only. iii. Total number of candidates that ...

physics
How much work must an ideal refrigerator perform to make 1 kg of ice at -10C from 1 kg of water at 20C when 20C is also its exhaust temperature?

Physics
what metal is it if, it is 7.14g/mL => Cast Iron.

Physics
I understand this question: 4. If a pendulum completes 40 vibrations in a minute, what is its period? The period is the time for one complete cycle, and if the pendulum takes one minute (or 60 seconds) for 40 vibrational cycles, then it must take 1.5 seconds for one complete ...

Physics
If a man travels 7km N 40degree W and 10km East, find the resultant displacement.

physics
a Coper wire with wire with a diameter of 1.5mm is joined to an alluminium wire, which has a diameter of 2.3mm. The wire carries a current of 1.2A. What is the current density in each wire?

Physics
Two blocks of masses 2.9kg and 3.9 kg are held by string upper and lower and given the acceleration 0.2 in upward direction gind tension

Physics
Hello, I really don't get something about work and I would like that someone help me, Please. .. Well I have an exercise about two objects that are connected by an ideal rope that pass through a pulley that has a moment of inertia, so my problem is: when I use "energy" to get ...

Physics
Work done by conservative forces change only A)PE of the system B)KE of the system C) ME of the system D)None of these

Physics
A simple pendulum is oscillating with an angular amplitude 60°.If mass of bob is 50 gram the tension in the string at mean position is(g=10m/s2)

physics
A boat of mass 40 kg is at rest.A dog of mass 4 kg moves in the boat with a velocity of 10 m/s.what is the velocity of the boat?

Physics
Capacitor c1 and c2 are 4f and 2f respectively are charged as series combination across 100v battery. The two capacitors are disconnected from each other.They are connected +ve plate to +ve plate and -ve plate to -ve plate.calculate the resulting charge on each capacitor

physics
Geostationary satellites are placed on orbits of radius 4.2×10^4m use this information to deduce g, the acceleration of freely falling body, at this height.

Physics
How long does it take for sound to travel around the world ?

Science (physics)
The driver of a car travelling along a straight road with a speed of 72km/hour observe a signboard which give a speed limit to be 54 km/hour. The sign board is 70m ahead when the driver applies the break calculate the acceleration of the car which will cause the car to pass ...

Physics

physics
What should be the minimum initial velocity with which a missile has to be launched so that it reaches a target of 1000km away in the same plane

physics
A geostationary satellite for communications seems to be in a fixed spot above the equator because it has the same angular velocity as the earth.A) show that if it goes round once a day,its angular velocity is a little over 7Ã—10 race to negative 5 rad per second

Physics
A lump of lead with mass 0.5kg is dropped from height of 20m onto a hard surface it doesn't rebound but remains there at rest for a long period of time. A, find change in heat , change in work, change in internal energy for the lead during this process?

physics
A pendulum suspended from the roof of a bus moving along a horizontal track makes an angle of 5° with the vertical,,,determine the acceleration of the bus?

physics
A child of mass 40kg jumps off a wall and hits the ground at 4m/s he bends his knees and stops in 1s calculate the force required to slow him down how would this force be different if he didn't bend his knees and stopped in 0.1s

Science: Physics
We use an electric immersion heater to heat 2,0 liters water having temperature of 20C to the boiling point. Specific heat capacity of water is 4,19 kJ/(kg c). The power of the heater is 1,50 kW and efficiency of heating is 80 %. How much time does the heating take?

Science: Physics
An electric heater of power 2500 W is connected to a voltage of 230 V. i) Calculate the electric current going through the heater. ii) What is the resistance of the heater? iii) How much energy does it consume in a year, if it is switched on 15 min every day. iv) How much it ...

Physics
A lump of lead with mass 0.5kg is dropped from height of 20m onto a hard surface it doesn't rebound but remains there at rest for a long period of time. A, find change in heat , change in work, change in internal energy for the lead during this process?

Physics
1. A rectangular coil 0.065 m by 0.080 m is positioned so that its cross-sectional area is perpendicular to the direction of a magnetic field. The coil has 66 turns and a total resistance of 7.6 Ω and the field decreases at a rate of 2.5 T/s. What is the magnitude of the ...

Physics
A 50 N box is pushed 5 m up a 30 degree inclined plane. What work is done on the box?

physics
Heather and Jerry are standing on a bridge 51 m above a river. Heather throws a rock straight down with a speed of 17 m/s . Jerry, at exactly the same instant of time, throws a rock straight up with the same speed. Ignore air resistance. How much time elapses between the first...

Physics -HELP
1. A rectangular coil 0.065 m by 0.080 m is positioned so that its cross-sectional area is perpendicular to the direction of a magnetic field. The coil has 66 turns and a total resistance of 7.6 Ω and the field decreases at a rate of 2.5 T/s. What is the magnitude of the ...

Physics -HELP
A rectangular coil 0.065 m by 0.080 m is positioned so that its cross-sectional area is perpendicular to the direction of a magnetic field. The coil has 66 turns and a total resistance of 7.6 Ω and the field decreases at a rate of 2.5 T/s. What is the magnitude of the ...

Physics -HELP
A coil with 337 turns of wire, a total resistance of 47 Ω, and a cross-sectional area of 0.35 m2 is positioned with its plane perpendicular to the field of a powerful electromagnet. What average current is induced in the coil during the 0.30 s that the magnetic field drops ...

physics
A certain vehicle can accelerate from rest to a speed of 25m/s in a time of 8s.What average power is needed to cause this acceleration?Neglect frictional losses

physics
A copper wire has a resistance of 1.02 Ω at 20.0°C. What is its resistance at 60°C? The temperature coefficient of resistivity for copper is 0.0039 (C°)—1.

physics
State the factors that affect the speed and the rotation of the motor

physics
At ground level g is 9.8meter per second square. Suppose the earth started to increase its angular velocity. How long would a day be when the people on the equator were just 'thrown off' why is the expression thrown off is a bad one?

Physics
A 13 kg block(mA) rests on a level table. The coefficient of kinetic friction between the block and the table is .15. A string of negligible mass is attached to the block. The string, which is perfectly horizontal, passes through a frictionless pulley at the edge of the table ...

maths, geography, physics, chemistry
A cuboid has TSA 40 sq. m and latral surface 26 sq. m. Find the base area.

physics
In Figure 10-1, if the force exerted on a 3.0-kg backpack that is initally at rest is 20.0 N and the distance it acts over is 0.25 m, what is the final speed of the backpack?

physics
A projectile is fired from the origin (at y = 0 m) as shown in the diagram. The initial velocity components are and The projectile reaches maximum height at point P, then it falls and strikes the ground at point Q, which is 20 m below the launch point. Assuming air resistance ...

physics
If a battary of 12vo and 100Ah is used for a 3KVA inverter calculate the maximum current it can produce at maximum load.

Science - physics
If you had to send your laser around a wide corner, which type of mirror could help? Briefly explain how it may help I think this one is a concave mirror

physics (science)
A body travels from rest with acceleration 8m/s square . Find its velocity when it has covered a distance of 100m

Physics
A 5.0 kg block with a speed of 2.9 m/s collides with a 10 kg block that has a speed of 2.1 m/s in the same direction. After the collision, the 10 kg block is observed to be traveling in the original direction with a speed of 2.6 m/s. Suppose, instead, that the 10 kg block ends...

physics
A car slows down uniformly from a speed of 24.0 m/s to rest in 4.50 s. How far did it travel in that time?

physics
Two forces ,whose resultant is 100N are perpendicular to each other .if one of them makes an angle of 60degrees with the resultant calculate its magnitude

Physics
9. Figure shows an aluminium wire of length 60 cm joined to a steel wire of length 80 cm and stretched between two fixed supports. The tension produced is 40 N. The cross-sectional area of the steei wire is 1.0 mm2 and that of the aluminium wire is 3.0 mm2. The minimum ...

Physics
A double-slit experiment uses coherent light of wavelength 633 nm with a slit separation of 0.100 mm and a screen placed 2.0 m away.

Physics
Hello, Could anyone help me with something about rolling motion? Well the question is the next: Does static friction cause a positive work in the rolling motion? I really don't get how the static friction is involved in rolling and if it causes work Please help

Physics
A car is traveling at 50km/h. The driver sees a child run out into the road 5m ahead. She applies the breaks and the car stops in 5s. The driver's thinking time is 1.5s. a. Will the car stop in time? b. If the driver's thinking time is increased to 2.5s, will the car stop in ...

Physics
At ground level g is 9.8m/s^2. Suppose the earth started to increase its angular velocity. How long would a day be when people on the equator were just 'thrown off'? Why is the expression 'thrown off' a bad one ?

Physics
At ground level g is 9.8m/s^2. Suppose the earth started to increase its angular velocity. How long would a day be when people on the equator were just 'thrown off'? Why is the expression 'thrown off' a bad one?

Physics
the co efficient of friction of a plane inclined at 30 degree is 0.4 . Then the acceleration of the body sliding freely on it is?

Physics
An electric fan is rated 240W,25V.Which fuse value is more suitable for the set

Physics
A 650 kg roller coaster car has two points of reference given to an observer. Point A, at a height of 120 m, the cart is moving at 3.40 m/s. Later on in the ride, at point B, the cart is moving at 28.2 m/s. Determine the height at point B. None of the formulas on my formula ...

Physics uncertainties
A flat head drill bit is used to drill holes of small depth. The drill bit can drill holes with a diameter size of (40 ± 0.5)mm. The depth of the hole has an uncertainty of ±1mm. If the total percentage uncertainty of the volume made by the hole is less than 10%, what is the...

Physics wave motion
A radar array consists of five vertical antennae arranged in a line, each emitting radio waves of frequency 120MHz in phase with one another uniformly in all directions. The spacing between each of the antennae is 8.0m. Apart from the normal direction perpendicular to the line...

Physics (pressure)
A barometer has air trapped above the mercury in an inverted tube with the opening in a reservoir of mercury. When the length l of air trapped is 10.0cm, the mercury height h is 72.0. When the tube is slightly lowered into the reservoir, l becomes 8.0cm. What is the new h? ...

Physics
This is an Oscillations question. A horizontal plate is vibrating vertically in simple harmonic motion at a frequency of 20Hz. What is the maximum amplitude of vibration so that a coin of 0.0080kg resting on the plate always remains in contact with it?

physics
An object of mass 0.50 kg on the end of a string is whirled round in a horizontal circle of radius 2.0m with a constant speed of 10m/s.Find its angular velocity and tension in the string( string is horizontal)answer should be 25.5 N

Physics
1.7 m long pendulum is setup from a 3 m ceiling so that it is at its peak (h=.65 m), it is then released. At the bottom of the swing the string is cut (assume no engery loss during the cutting process) 1.) what is vertical velocity right before it hits the ground? 2.) how far ...

physics
A soccer ball was kicked off a cliff that was h = 8.4 m above the ground. The ball was kicked at a speed of 25 m s-1 and an angle of 20 to the horizon. What is magnitude of the horizontal displacement of the ball? Use g = 9.8 m s-2. proper equation and help plz

physics
Charlie now moved onto the next hole where he hit the ball with an initial speed of 30 m s-1 and at an angle of 60 degrees. This time the ball lands with a speed of 17.3 m s-1. Use g = 9.8 m s-2.

PHYSICS
Charlie now moved onto the next hole where he hit the ball with an initial speed of 30 m s-1 and at an angle of 60 degrees. This time the ball lands with a speed of 17.3 m s-1. Use g = 9.8 m s-2.

PHYSICS
Terry hit his 26 g golf ball so that it has an initial velocity of 33 m s-1 travelling at an angle of 26 to the horizon. If the ball lands at the same height it was struck, how far will it travel? Use g = 9.8 m s-2.

PHYSICS HELP!!!!!
A soccer ball was kicked off a cliff that was h = 8.4 m above the ground. The ball was kicked at a speed of 25 m s-1 and an angle of 20 to the horizon. What is magnitude of the horizontal displacement of the ball? Use g = 9.8 m s-2. proper equation and help plz

PHYSICS HELP
A pilot wants to fly a plane east at a velocity of 400.0 km/hr with respect to the ground. A 50.0 km/hr wind is blowing southward. With respect to the air, what velocity must the pilot maintain?

physics
A soccer ball was kicked off a cliff that was h = 8.4 m above the ground. The ball was kicked at a speed of 25 m s-1 and an angle of 20 to the horizon. What is magnitude of the horizontal displacement of the ball? Use g = 9.8 m s-2.

physics
A brick is dropped (zero initial speed) from the roof of a building. The brick strikes the ground in 3.05 s. You may ignore air resistance, so the brick is in free fall. (a) How tall, in meters, is the building? (b) What is the magnitude of the brick's velocity just before it ...

physics hw
Determine the stopping distances for a car with an initial speed of 87 km/h and human reaction time of 2.0 s for the following accelerations. (a) a = -4.0 m/s2 (b) a = -8.0 m/s2

physics
A car starts from rest and travels for 5.0 s with a uniform acceleration of +2.5 m/s2. The driver then applies the brakes, causing a uniform negative acceleration of -3.0 m/s2. If the brakes are applied for 2.0 s, how fast is the car going at the end of the braking period, and...

Physics- Energy Released In Chemical Reaction
The reaction between two hydrogen isotopes is shown below: 2H + 3H → 4He + n + energy released The energy released in this reaction is: a.equal to that in a fission reaction b.equal to that in a chemical reaction. c.less than that in a chemical reaction. d.greater than that ...

Physics- Car moving with speed of 22 m/s...
A car is moving with a speed of 22 m/s. The driver then brakes, and the car comes to a halt after 6.5 s. What is the distance covered by the car after the driver brakes, until it comes to a stop? a. 36 m b. 72 m c. 140 m d. 219 m

Physics-Uncertainty Principle
On the subatomic level, the uncertainty principle creates situations in which ___________ does not apply.

Physics
A model rocket has a mass of 0.435 kg. It is mounted vertically and launches directly up with a thrust force of 13.1 N. a) What is the weight of the rocket? b) Determine the net force on the rocket as it is launched. c) What is the acceleration of the rocket at lift-off?

physics
An ore car of mass 41000 kg starts from rest and rolls downhill on tracks from a mine. At the end of the tracks, 29 m lower vertically, is a horizontally situated spring with constant 4.1 × 105 N/m. The acceleration of gravity is 9.8 m/s2 . Ignore friction. How much is the ...

Physics
A cardboard box of unknown mass is sliding upon a mythical frictionless surface. The box has a velocity of 4.56 m/s when it encounters a bit of friction. After sliding 0.700m, the box has a velocity of 3.33 m/s. What is the coefficient of friction of the surface? Am I right to...

Physics
A football is kicked at ground level with a speed of 17.7 m/s at an angle of 39.8 ∘ to the horizontal. How much later does it hit the ground? Answer=> t=_____ s Express your answer using three significant figures and include the appropriate units.

Physics
Problem: A person has a reasonable chance of surviving an automobile crash if the deceleration is no more than 30 "g's. Part A: Calculate the magnitude of the force on a 71-kg person accelerating at this rate. Answer=> F= 2.09x10^4 N Part B: What distance is traveled if ...

physics
A train travelling at 30km/h stops when it's brakes are applied. The train suffers a deceleration our 2m/s. @. How long does the train take to come to rest? b) what is its final velocity?

physics
a circular wheel rotate 200 nos. of revolution in 30 seconds. find its angular velocity