# Homework Help: Science: Physics

## Recent Homework Questions About Physics

**physics**

The efficiency of a machine is 80%. Determine the work done by a person using this machine to raise a load of 200kg through a vertical distance of 3.0 (take g = 10m/s)

**Physics**

A battery is used in an experiment and is connected by a 37.5 cm long gold wire with a diameter of 0.590 mm. If the battery has a voltage of 1.70 V and the resistivity of the wire is 2.4×10-8 Ω m, what is the current in the wire?

**physics**

A ballet student with her arms and a leg extended spins with an initial rotational speed of 1.2 rev/s . As she draws her arms and leg in toward her body, her rotational inertia becomes 0.80 kg⋅m2 and her rotational velocity is 3.9 rev/s .Determine her initial rotational ...

**physics**

An extremely dense neutron star with mass equal to that of the Sun has a radius of about 10 km −about the size of Manhattan Island. These stars are thought to rotate once about their axis every 0.03 to 4 s, depending on their size and mass. Suppose that the neutron star ...

**Physics 2017**

I have a coil of copper wire. I want to know the length of the wire in the coil. I do not wish to unwind the coil and measure the length directly. I find from a table of densities that the density of copper is 8.89x10^3kg/m^3. Explain how I could find the length of wire.

**physics**

3 charges are placed in a equilateralABC of side l.a point is kept between the sideBc such that the chargeA remains.find the magnitude and sign of the point charge

**physics**

A golf ball of mass 125g hits a billards ball of mass 172.5g that is initially at rest. after the colision, the golf ball moves to the right at a speed of 10cm/s. the billards ball moves to the left with a speed of 58 cm/s. (a) What was the velocity of the golf ball before the...

**Physics**

A steel beam that is 7.00 m long weighs 352 N. It rests on two supports, 3.00 m apart, with equal amounts of the beam extending from each end. Suki, who weighs 595 N, stands on the beam in the center and then walks toward one end. How close to the end can she come before the ...

**physics**

A 10-kg disk-shaped flywheel of radius 9.0 cm rotates with a rotational speed of 320 rad/s. Determine the rotational momentum of the flywheel. With what magnitude rotational speed must a 10-kg solid sphere of 9.0 cm radius rotate to have the same rotational momentum as the ...

**physics**

A star the size of our Sun runs out of nuclear fuel and, without losing mass, collapses to a white dwarf star the size of our Earth. The radius of our Sun is 6.96×108m , the radius of Earth is 6.37×106m If the star initially rotates at the same rate as our Sun, which is once...

**physics**

A thin plate glass window with a refractive index 1.5 is tapered at a 5° angle. You are looking from the outside through such a window at an angle of 30° with respect to the normal and see a person standing there behind the window (very similar to the fish tank we discussed ...

**Physics**

When interference happens with two monochromatic light waves, which of the following is a characteristic of the amplitude of the resultant wave? a. it is zero. b. it is equal to the sum of the amplitudes of the component waves. c. less than the amplitude of either of the ...

**physics**

A student with mass (72.0) kg rides on a roller coaster with a vertical loop. At the top of the loop the track has a radius of (23.7) m and the roller coaster moves at speed of (25.9) m/s at the top. Determine the normal force from the seat on the student at the top of the ...

**physics**

A bicyclist with mass (72.0+C) kg wants to make a turn with a radius of (27.5) m on a horizontal surface. If she is riding at a speed of (14.45) m/s, at what angle from the vertical will she need to lean to make the desired turn? Give your answer in degrees and with 3 ...

**physics**

A car with mass (452) kg attempts to make a turn with a radius of (31.8) m at a speed of (21.5) m/s on a horizontal surface. What is the minimum value for the static coefficient of friction between the tires and the roadway necessary for the car to make the turn without ...

**physics**

Consider an object with a mass of 12.5 kg moving at a constant speed in a circular path with a radius of <11.30> m. The object makes one full revolution in <16.60> seconds. Calculate the centripetal acceleration of the object. Give your answer in m/s2 and with 3 ...

**Physics**

A thin light beam is shining onto a wall. You take a solid block of glass that is 3.0cm thick and place it between the wall and the beam. The refractive index of the glass is 1.5. The angle between the beam and the surface of the block is 60° What is the incident angle of the...

**physics**

Spaceship 1 and Spaceship 2 have equal masses of 300 kg. Spaceship 1 has a speed of 0 m/s, and Spaceship 2 has a speed of 4 m/s. What is the magnitude of their combined momentum?

**physics**

If a car has a mass of 400 kg and a velocity of 30 m/s to the east, what is the magnitude of its momentum?

**Physics**

A father and son sitting on opposite sides of a seesaw balance each other. What is the father's weight if he is seated at 0.5m away from fulcrum and son is seated at 1.5m away from the fulcrum and weighs 200N?

**physics**

In using a pulley system, an effort of 100N is needed to raise steadily a load of 800N (a) what is the mechanical advantage?. Data effort=100N load=800N M.A=load/Effort M.A=800N/100N M.A=8

**Physics**

If the trampoline can be considered as a spring with a spring constant of 4.5 x 10^5 N/m, what is the maximum depression of the trampoline? I started with this knowledge: E=1/2mv^2+mgy+1/2kx^2 This being the total of energies. I have done a similar problem in an example ...

**Physics!**

Question #4 : What is the amount of energy used to raise a 3000N load 0.4m? A force of 1000N is used to raise that same load up. 1)State the mechanical advantage of the machine used? 2)Is this machine 100% efficient?

**Physics**

A horizontal spring(k= 86.2 N/m) is placed on a countertop and is compressed a distance of 36.3 cm. A 103.5 g object is placed at the end of the spring. The coefficient of kinetic friction between the object and countertop is measured to be .47. What acceleration will the ...

**ap physics**

A Verdant Power water turbine (a "windmill" in water) turns in the East River near New York City. Its propeller is 2.5 m in radius and spins at 32 rpm when in water that is moving at 2.0 m/s. The rotational inertia of the propeller is approximately 3.0 kg⋅m2.Determine the ...

**ap physics**

Determine the change in rotational kinetic energy when the rotational velocity of the turntable of a stereo system increases from 0 to 33 rpm. Its rotational inertia is 6.8×10−3kg⋅m2 .

**ap physics**

Suppose that Superman wants to stop Earth so it does not rotate. He exerts a force on Earth F⃗ SonE at Earth's equator tangent to its surface for a time interval of 1 year. The mass of Earth is 5.98×1024kg, the radius is 6.37×106m. Assume that Earth is a solid sphere with ...

**ap physics**

A 10-kg disk-shaped flywheel of radius 9.0 cm rotates with a rotational speed of 320 rad/s. Determine the rotational momentum of the flywheel. With what magnitude rotational speed must a 10-kg solid sphere of 9.0 cm radius rotate to have the same rotational momentum as the ...

**Physics**

Pepe and Alfredo are resting on an offshore raft after a swim. They estimate that 3m separates a trough and an adjacent crest of surface waves on the lake. They count 14 crests that pass by the raft in 20 seconds. Calculate how fast the waves are moving.

**ap physics**

A star the size of our Sun runs out of nuclear fuel and, without losing mass, collapses to a white dwarf star the size of our Earth. The radius of our Sun is 6.96×108m , the radius of Earth is 6.37×106m . If the star initially rotates at the same rate as our Sun, which is ...

**ap physics**

Suppose that a person closes a car door. The person's fingers are in the door opening, that is located 0.50 m from the hinges. The rotational inertia of the car door is 5.0 kg⋅m2. The door closes in 0.1 s and the rotational speed of the door is 1.4 rad/s just before it ...

**ap physics**

A car leaves an intersection after a light turns green. It starts from rest and reaches a speed of 13.4 m/s in 5.0 s. The radius of a tire of the car is 0.25 mDetermine the average rotational acceleration of the tire.

**ap physics**

A car leaves an intersection after a light turns green. It starts from rest and reaches a speed of 13.4 m/s in 5.0 s. The radius of a tire of the car is 0.25 m.

**Physics**

A ball is thrown with a speed of 19m/s and at an angle of 46 degrees. How high does it go above the cliff to the nearest tenth?

**Physics**

If the distance between two charges is increased to three times the original distance, how will the electrical force between the charges compare with the original force? It will increase to three times the original force. It will increase to nine times the original force. It ...

**Laws of Physics**

A box is pushed 2.1m up a ramp into a container by an effort force of 200N. The container gains 200N. 1)What is the energy used to push the container? 2)What is the efficiency of the machine? 3)What force can affect the load when it is being pushed?

**Physics**

Blood from an animal is placed in a bottle 1.3 m above a 3.6 cm long needle, of inside diameter 0.35 mm , from which it flows at a rate of 2.1 cm3/min . What is the viscosity of this blood? Assume ρblood=1.05×103kg/m3.

**Physics**

Find work done when 25kg weight lifted to a vertical height of 2m from the ground carrying to the same place by pushing it up and inclined plane make the angle of 30 degree (g=9.8)

**Physics - Forces**

A 10 kg block is pressed against a vertical wall and held in place by a force F of 180 N, 37° above the horizontal. The coefficient of static friction μS=0.20. Find the magnitude and direction of the frictional force. The answer is 10.3 N downward but I don't know how to ...

**Physics**

A man pushes a 200 N crate up a frictionless incline with a slope of 20 degrees. The crate is raised by 4 m as shown. Assuming the crate moves at constant speed, what is the work done by the man?. I know Work = Force x Displacement. The answer is 800 N. Why is the displacement...

**Physics**

A hydraulic hoist has a ram of 30 cm diameter and a plunger of 1 cm diameter. If 70 N effort is applied to the plunger and the efficiency is 80%, find the maximum load it can raise.

**Physics**

show that, the tangent of the angle of friction is equal to the coeficient of friction.

**Physics**

when loading a toy launcher, a spring is pulled back 15 cm. the spring is known to have a spring constant of 315 N/m. A small object of mass 4.46 g is place at the end of the spring. What acceleration will the object experience the instant the spring is released?

**Physics**

A flywheel turns through 60 rev as it slows from an angular speed of 2.8 rad/s to a stop. How much time is required for it to complete the first 30 of the 60 revolutions?

**Physics**

A box is suspended by a string from the ceiling of an elevator. The string supports the box with a force of 17.0 N when the elevator is accelerating downwards at 1.70 m/s2. What force would the string exert if the elevator was moving upwards at a constant velocity

**Physics**

You are skiing down a down a slope angled at 30o to the horizontal. You acceleration is 2 m/s2. What is the coefficient of kinetic friction between you and the hill?

**Physics**

The A box is being pulled by a rope across a level floor as shown in the diagram. The box is accelerating at 1 m/s2, the coefficient of kinetic friction is 0.5. What is the tension in the rope?

**Physics**

What is the linear acceleration of a point on the rim of a 38 cm-diameter record rotating at 33 1/3 rev/min?

**Physics**

a thin metal ring of diameter is 0.6m and mass 1 kg starts rest and rolls down inclined plan.Its linear velocity is 5m/s .Calculate the moment of inertia and kinetic energy of rotation.

**physics**

The speed of light is measured to be 1.50 ×108 m s–1 in a sucrose water solution. Calculate the refractive index of the solution.

**Physics**

A sphere of radius r =5cm and volume charge density ρ=14μC/m^3 spins at ω=200rad/s . What is the magnetic field at the center of the sphere in Tesla?

**Physics**

Consider classical electron orbit with radius 53pm (picometers) that has a magnetic moment equal to sqrt(2)*μB (the Bohr magneton). What is the current of that orbiting electron in A?

**Physics**

The femoral artery carries blood to the leg and has a diameter of 12.5 mm. What is the resistance in a column of blood that is 2.20 cm long if the conductivity of blood is 0.630 Ω-1m-1?

**Physics**

A force of 132 new inns is applied in pushing a stalled autoMobile at constant speed for a distance of 150 m. How much work is done in joules on the car by the force ?

**physics**

A beer is dropped from a window 30 m above the ground. How fast will it be moving just before it lands? (Neglect air resistance).

**Physics**

Do the electrons in an ion of nitrogen (such as N+ or N+2) have exactly the same permitted energy levels the electrons in a neutral nitrogen atom, and therefore, same absorption and emission lines?

**Physics**

Computer the power output in watt of a machine that lift a 50kg crete through a height of 20cm in 1minute

**Physics**

A traveler pulls on a suitcase strap at an angle 28° above the horizontal. If 1,266 J of work are done by the strap while moving the suitcase a horizontal distance of 50 m, what is the tension in the strap?

**Physics**

An 103 Newtons box of oranges is being pushed across a horizontal floor. As it moves, it is slowing at an acceleration of -0.9m/s2. The push force has a horizontal component of 20N and a vertical component of 25N downward. Calculate the coefficient of the kinetic friction and ...

**Physics**

Ten litre of water per second is lifted from well through 10m and delivered with a velocity of 10m/s if g=10m/s^2. The power of motor is Answer 1.5Kw how ??

**Physics**

In a rectangular coordinate system, a positive point charge 5.0 nC is placed at the point x=0, y=2.0 cm, and a negative point charge -5.0 nC is placed at x=0, y=-2.0 cm. Both charges have masses 4.0x10^-3 g. Point P is at x=3.0 cm, y=2.0 cm. The electric potential at infinity ...

**Physics**

A 23.7 kg child, with a 4.35 kg backpack on his back, first stands on a sidewalk and then jumps up into the air. Find the net force (positive up/negative down) on Earth due to the child when the child is (c) standing still and (d) in the air.

**Physics**

Two resistors, 6 ohms and 18 ohms are connected in parallel and the combination is connected in series with a 2 ohm resistor. Find the current through each of the first two resistors if the current through the 2 ohm resistor is 1.2 ampere. What is the voltage across each ...

**physics**

Cylinder water tank 80cms height 1000liters what is its diameter

**Physics**

A girl of mass 25kg runs up a stress of total height 3.0m.find the work done against gravity.

**physics**

A person kicks a rock off a cliff horizontally with a speed of 20 m/s. It takes 7.0 seconds to hit the ground, find: a) height of the cliff b) final vertical velocity c) range

**Physics**

What happens to the focal length of a converging lens as the radius of curvature is increased?

**Physics**

You get a summer internship working with a 589.2nm laser (an intense light source with a very well defined wavelength). You want to spray some oil with noil=1.25 on your glasses with nglass=1.50 as an additional safety feature to protect you from accidental flashes of laser ...

**Physics 202**

You get a summer internship working with a 589.2nm laser (an intense light source with a very well defined wavelength). You want to spray some oil with noil=1.25 on your glasses with nglass=1.50 as an additional safety feature to protect you from accidental flashes of laser ...

**physics**

Objects deep beneath the surface of the ocean are subjected to extremely high pressures. Some bacteria in these environments have adapted to pressures as much as a thousand times atmospheric pressure. How might such bacteria be affected if they were rapidly moved to the ...

**Physics**

Make a position vs time graph of the following scenario: an object moves at 5.0 m/s for 4.0 s then at -2.0 m/s for 3.0 s.

**Physics**

a 24kg metal ring with 24cm diameter rolls without stopping down a 30 degree incline from a height of 3.4 m 1) according to the law of conservation of energy what should be the linear speed of the ring at the bottom of the ramp (I'm guessing that i solve for Vfrictionless, ...

**Physics**

Find speed of sound in air if distance is 170 meters and time is 1.1 second

**physics**

A car tire makes contact with the ground on a rectangular area of 12cm by 18cm and the pressure exerted on the ground by the car is 1.05 x 10^5 Pa . the car mass is ..........

**Physics**

Problem: A fixed 16.2-cm-diameter wire coil is perpendicular to a magnetic field 0.79 T pointing up. In 0.15 s , the field is changed to 0.34 T pointing down. Part A: What is the average induced emf in the coil?

**Physics**

A 20-cm-diameter circular loop of wire is placed in a 0.57-T magnetic field. Part A When the plane of the loop is perpendicular to the field lines, what is the magnetic flux through the loop? Part B The plane of the loop is rotated until it makes a 42 ∘ angle with the field ...

**Physics**

An air-filled toroidal solenoid has a mean radius of 15.2 cm and a cross-sectional area of 4.98 cm2 as shown in (Figure 1) . Picture this as the toroidal core around which the windings are wrapped to form the toroidal solenoid. The current flowing through it is 11.5 A , and it...

**Physics**

The ice point of a faulty mercury in glass thermometer isX degree celcius while its steam point is 85 degree celcius. If the thermometer reads 50 degree celcius when the true temperature is 40 degree celcius, calculate the value of X

**physics**

Object A of mass M is released from height H, whereas object B of mass 0.5M is released from height 2H. What is the ratio of the velocity of object A to that of object B immediately before they hit the ground? A. 1 : 2 B. 1.41 : 1 C. 1 : 1.41 D. 1 : 4 E. 1 : 1

**physics**

Mass M1 has twice the mass of M2. M1 and M2 are raised from a height of 5 m to 25 m, and from 14 m to 24 m, respectively. What is the ratio of work done on mass M1 to that done on mass M2? A. 1 : 4 B. 25 : 12 C. 4 : 1 D. 2 : 1 E. 5 : 1

**physics**

At what rate is a 60.0-kg boy using energy when he sprints up a flight of stairs 10.0 m high in 8.00 s? A. 75.0 W B. 48.0 W C. 735 W D. 480 W E. 4.80 kW

**physics**

A 10-kg mass is moving at a speed of 4.0 m/s. How much work is required to stop the mass? A. 20 J B. 40 J C. 60 J D. 80 J E. 100 J

**physics**

Which quantity and unit are INCORRECTLY paired? A. Quantity: F Unit: kg m/s B. Quantity: J Unit: N·s C. Quantity: W Unit: J D. Quantity: P Unit: W E. Quantity: E Unit: kg m2/s2

**physics**

In which of the following situations is the most work done on the object? A. Holding a 50 kg object. B. Carrying a 30 kg object down a 40 m long hallway. C. Lifting a 20 kg object 1 m up. D. Carrying a 15 kg object up a flight of stairs. E. Lowering a 25 kg object from a ...

**Physics**

p = mv Scenario #4 At a station ,a train weighs approximately 1000kg and is moving at 50m/s on a railway and collides with an incoming train weighing 1000kg and moving at -20m/s. 1)If these two trains stick together and begin to move after having being collided with one ...

**physics 11**

a water bomber flying with a horizontal speed of 85m/s at a height of 3000 m drops a load on a fire below. how far in front of the target fire should the load be released?

**physics 11**

a canon is shot horizontally at 15 m/s off a cliff, which is 36m above water. how far away from the cliff should the target enemy boat be when the canon is shot?

**Physics**

Scenario : A truck has a mass of 2000kg and is moving at 50m/s and collides with another truck that has a mass of 2000kg moving at a speed of -20m/s. 1)Is this a sticky or springy collision? 2)What is the total momentum after the collision? 3)If both trucks stick together and ...

**Physics**

A(n) 0.34 kg soccer ball approaches a player horizontally with a speed of 6.18 m/s. The player illegally strikes the ball with her hand and causes it to move in the opposite direction with a speed of 31.3 m/s . What is the magnitude of the impulse de- livered to the ball by ...

**Physics**

Three resistors are connected in series across a battery. The value of each resistance and its maximum power rating are as follows: 7.1Ω and 20.9 W, 29.5Ω and 11.4 W, and 13.6Ω and 12.5 W. (a) What is the greatest voltage that the battery can have without one of the ...

**physics**

Determine the ionization energy required to extract the electron totally out of a hydrogen atom, and put it at rest

**physics**

A 60kg boy climbs 70 fligts of stairs each 20cm high in one minute how much powers is developed?

**physics help please**

A double-slit experiment is performed with light from a Helium Neon Laser on two slits 80 micrometers apart. The first bright interference fringe left of the center is spaced 2m from the bright center. How far away from the double slit is the screen? wavelength =632nm What ...

**Physics**

Things around you are emitting infrared radiation that includes the wavelength 1.13 10-5 m. What is the energy of the photons?

**Physics PLEASE HELP**

The two barges shown here are coupled by a cable of negligible mass. The mass of the front barge is 2.22 ✕ 10^3 kg and the mass of the rear barge is 3.22 ✕ 10^3 kg. A tugboat pulls the front barge with a horizontal force of magnitude 34.0 ✕ 10^3 N, and the frictional ...

**physics**

After a mishap, an 82.8 kg circus performer clings to a trapeze, which is being pulled to the side by another circus artist, as shown here. (angle for T1 = 15) (angle for T2 = 10) Calculate the tension (in N) in the first rope,T1, if the person is momentarily motionless. (...

**Physics**

A 35.0 g ball at the end of a string is swung in a vertical circle with a radius of 35.0 cm. The rotational velocity is 212.0 cm/s. (a)Find the tension (in N) in the string at the top of the circle. (b)Find the tension (in N) in the string at the bottom of the circle.

**Physics**

A car is traveling with constant 20.0 ms for 2.0mins constant rate 0.50 how far can travel for first part of the trip How long does it take for the car to a stop during the decond part of trip How far does it take during second trip What average velocity

**Physics**

A 1500 kg car is combined to another car of mass of 1000 kg by colliding with it at a velocity of 3 cm/sec.Find the velocity of the cars just after their collision.

**physics**

A student pulls a (34) kg box a distance of (13.50) m up a ramp set at 25.8o using a force of (181) N applied parallel to the ramp. Find the efficiency of the ramp. Give your answer in percent (%) and with 3 significant figures.