# Homework Help: Science: Physics

## Recent Homework Questions About Physics

**modern physics**

Missiles are fired towards the earth from a spacecraft. The missiles are moving with a speed of 0.8c with respect to the spacecraft. If the spacecraft itself has a speed of 0.3c with respect to Earth, how fast are the missiles observed to travel with respect to Earth? What ...

**modern physics**

Supersonic jets are able to achieve maximum speeds of up to 3.0 × 10-6c. Calculate the percentage contraction in the length of a jet plane travelling at this speed.

**modern physics**

The earth and the sun are 8.3 light-minutes apart in the same inertial frame. Two events occur at t = 0 on the earth and t = 3 minutes on the sun respectively. Calculate the time difference between the events according to an observer moving at u = 0.6c from the earth to the ...

**Physics**

A Car is travelling 20m/s when it pulls out to pass a truck that is travelling at 18 m/s. The car accelerates at 2.0m/s^2 for 7.0 seconds B) What is the car's speed at the end of the period of acceleration? Vi=20 m/s Vf=18 m/s a= 2.0m/s^2 t=7.0 Seconds I am unsure what formula...

**Physics**

an empty measuring cylinder weighs 100g. When it contains 20cm^3 of liquid it weighs 120 g. a) What is the density of the liquid?

**physics**

An arc lamp operates at 80V . suggest a method to use it with 240 V d.c. source

**Physics/Mechanics**

A particle A of mass 150g lies at rest on a smooth horizontal surface. A second particle B of mass 100g is projected along the surface with a speed of u m/s and collides directly with A. On collision the masses coalesce and moves on with a speed of 4 m.s . find the value of u ...

**physics**

An arc lamp operates at 80V . suggest a method to use it with 240 V d.c. source

**Physics**

A transverse wave is formed on a long skipping rope. The equation of the transverse wave is y=5.50 sin(0.031π x+5.52π t) where x and y are in centimeters, t is in seconds, and Π is pi (3.14..). Find the amplitude of the wave? what is the wavelength of the transverse wave? ...

**physics**

How do you draw a force diagram for an object that is tied to a pole and is moving in a constant circular direction?

**Physics**

What is the direction of the displacement of a person who walks 10 km at 37 degrees south of east, then 14 km due west?

**Physics**

At what acceleration would you expect the blood pressure in the brain to drop to zero for an erect person? Why? (Assume there are no body mechanisms operating to compensate for such conditions)

**modern physics**

A radioisotope P has a half-life of 3 s. At t = 0, a given sample of this isotope contains 8000 atoms. Calculate (i) its decay constant, (ii) average life, (iii) the time t1 when 1000 atoms of the isotope P remain in the sample, and (iv) number of decays per second in the ...

**modern physics**

Calculate the deBroglie wavelength of a^ 87Rb atom that has been laser cooled to 120 µK. (Assume that the kinetic energy is .3/2kBT)

**modern physics**

A star emits light with wavelength 120 nm. An observer on earth measures the wavelength of the light received from the star to be 600 nm. Calculate the speed with which the star is moving.

**modern physics**

Missiles are fired towards the earth from a spacecraft. The missiles are moving with a speed of 0.8c with respect to the spacecraft. If the spacecraft itself has a speed of 0.3c with respect to Earth, how fast are the missiles observed to travel with respect to Earth? What ...

**modern physics**

The rest energy of a proton is 938 MeV. If its kinetic energy is also 938MeV, calculate its momentum and speed.

**modern physics**

Supersonic jets are able to achieve maximum speeds of up to 3.0 × 10-6c. Calculate the percentage contraction in the length of a jet plane travelling at this speed.

**modern physics**

The earth and the sun are 8.3 light-minutes apart in the same inertial frame. Two events occur at t = 0 on the earth and t = 3 minutes on the sun respectively. Calculate the time difference between the events according to an observer moving at u = 0.6c from the earth to the ...

**physics**

Two Small sphere are given positive electrical change. When they are 40cm apart the repulsion force between them has magnitude 0.25N what the charge on each sphere if two changes are equal

**physics**

Two boxes of masses 3kg and 8kg respectively are moving with velocities 5m/s and 3m/s in opposite direction. If they stick together after impact, calculate their common velocity.

**Physics**

The lenses used in a compound microscope have powers of + 110 D and + 60 D . If a total magnification of -150 × is desired, what should be the distance between the two lenses?

**Physics**

A spaceship travels through space at a constant velocity of 3.00 x 10^2 m/s. What is the net force acting on the spaceship?

**advance physics**

A carnot’s engine with air as working substance is initially at 3270C and pressure of 12 atmospheres. The volume is one litre to start with. The expansion or compression ratio is 1:6. Find the lowest temperature and efficiency. (γ= 1.4)

**physics 1**

) An oil tanker’s engines have broken down, and the wind is blowing the tanker straight toward a reef at a constant speed of 1.5 m/s (Fig.1). When the tanker is 500 m from the reef, the wind dies down just as the engineer gets the engines going again. The rudder is stuck, so...

**Physics**

4. Two vehicles of equal mass collide at a 90° degree intersection. If the momentum of vehicle A is 1.20x10^5 kg km/h east and the momentum of vehicle B is 8.50x10^4 kg km/h north, what is the resulting momentum of the final mass?

**Physics**

3. Two vehicles collide at a 90 degree intersection. If the momentum of vehicle A is 6.10 x10^5 kg km/h south and the momentum of vehicle B is 7.20 x 10^5 kg km/h east, what is the magnitude of the resulting momentum of the final mass?

**Physics**

2. Two pickup trucks crash at a 90 degree intersection. If the momentum of pickup A is 4.60 x10^4 kg km/h north and the momentum of pickup B is 6.25 x 10^4 kg km/h east, what is the magnitude of the resulting momentum of the final mass?

**Physics**

1.Two motorcycles of equal mass collide at a 90 degree intersection. If the momentum of motorcycle A is 450 kg km/h west and the momentum of motorcycle B is 725 kg km/h south, what is the magnitude of the resulting momentum of the final mass?

**physics**

Two Children,A and B, fire identical 10g ball bearing from a catapult. The elastic band of each catapult is elastically extended by 0.10m and then released to fire a the ball bearings. Child A's elastic band has a spring constant of 144 N/m. Calculate the energy transferred to...

**physics-lenses**

What eyeglasses would you prescribe for persons with the following conditions: a) A near point of 49.8cm ? b) A far point of 49.8cm ?

**physics-lenses**

A converging lens f1=10cm, is placed 25cm to the left of a diverging lens, f2=−15cm. An object is placed 22cm to the left of the converging lens. Locate the final image... in cm and its magnification. I'm not sure how to approach this problem, or the types of formulas I ...

**physics-lenses**

A converging lens of focal length 4.3 m produces a magnified image 6.7 times the size of the object. What is the object distance if the image is real? virtual? pleasse help!

**physics**

A <69.0> kg construction worker is standing on an 18.0 kg plank. The plank is <12.50> m long and it is suspended by vertical cables at each end. If the worker stands 2.80 from the right end of the plank, what is the tension in right cable? Give your answer in ...

**PHYSICS**

a stone of mass 0.5kg is drop from a height of 12m. calculate; it's kinetic energy. (g=10m/s2).

**Physics**

A wire runs left to right and carries a current in the direction shown. What is the direction of the magnetic field at point Z?

**Physics**

A positive charge moving up enters a magnetic field pointing out of the screen. What is the direction of the magnetic force on the charge? up down right left

**Physics**

What must be known to determine the direction of the magnetic force on a charge? the type of the charge the amount of the charge the direction of the magnetic field the velocity of the charge the strength of the magnetic field

**Physics**

The magnetic field 0.02 m from a wire is 0.1 T. What is the magnitude of the magnetic field 0.01 m from the same wire?

**Physics**

If a Wire Resistance is 10 ohm at 0 DegC and the same wire Resistance becomes 15 ohm at temperature 100 DegC, then at what temperature the wire Resistance will be 30 ohm? Temperature coefficient of the wire material is 0.0047.

**Physics**

Two point charges of 16 microcoulomb and - 9 microcoulomb are placed at8 cm distance. determine the position of the point at which resultant electric field is zero

**Physics**

When a 2Kg block of metal at 600°C is put into water at its boiling point, 0.5 kg of steam is released. Find the specific heat capacity of the metal?

**Physics**

Physics lab need help with sources of error. In our lab, we had to use carbon tape and a spark timer to find out the maximum velocity and maximum acceleration of a high school student. I'm having a hard time to find sources of errors. Any ideas or insights would be really ...

**physics**

A block is sent up a frictionless ramp along which an x-axis extends upward. The figure below gives the kinetic energy of the block as a function of position x. If the block’s initial speed is 4.00 m/s, what is the normal force on the block? (initial KE is 40J) initially i ...

**Physics**

A plane directly east at a velocity of 860 km/h for 45 min and then travels directly west with a velocity of 720 km/h for 1h and 30 min. Find the following values for this plane, expressed in km and km/h: a) Total displacement b) Total distance c) Average velocity d) Average ...

**physics**

A pulley system of 4 pulleys is used to raise a loan of mass 50kg vertically,if its effeciency is 80%,determine the minimum effort required to raise the load(g=10ms-2)?

**physics**

A soccer ball has a diameter of about 22 cm and a mass of about 430 g. What is its terminal velocity?

**Physics**

Given that charge of the electron is 1.6 x10^-19 C,What is the energy gained by the cathode ray particle when a voltage of 800 volts is applied between the electrodes of a cathode ray tube

**physics**

A stone of mass 2.8kg is projected upward with a speed of 5m/s. calculate the maximum height reached. use g=10m/s square.

**physics**

a uniform rod is 1m caring a weight of 100N calculate its tension of the string holding it an the reaction at the hinge

**physics**

How much positive and negative charge is there in a cup of water

**physics**

Find the relativistic momentum of an electron and proton accelerated through a potential of 10*10e6 Volts 10.5MeV/c , 137.4MeV/c 10.5MeV/c , 13.74MeV/c 105MeV/c , 13.74MeV/c 105MeV/c , 1.37MeV/c None of the above

**AP Physics**

A block and a spool have the same mass, and are each pulled across a level, frictionless surface by a string, as shown to the right. The string pulling the spool is wrapped around it many times, and the other string is fastened to the center of the block. Both hands pull with ...

**Physics**

A block and a spool have the same mass, and are each pulled across a level, frictionless surface by a string, as shown to the right. The string pulling the spool is wrapped around it many times, and the other string is fastened to the center of the block. Both hands pull with ...

**Physics**

A potter’s wheel with rotational inertia 24 kg m2 is spinning freely with no friction at 50 rpm. A piece of clay is dropped from above the wheel and sticks 0.5 m from the center of the wheel. Afterward, the rotational speed of the wheel and clay has dropped to 48 rpm. The ...

**Physics**

The game of Jacks is played with pieces like those shown to the right, consisting of four small spheres at the ends of two perpendicular rods of length L and mass M. The piece is spun as shown about an axis through the third perpendicular rod of length L and mass M. Assume ...

**Physics**

A wheel with rotational inertia I initially rotates with a angular speed ωi . A torque is applied, speeding the wheel up to three times the angular speed in time Δt . A) Find the magnitude of the applied torque. B) Find the work done on the wheel during this time.

**Physics**

A hamster sits 0.10 m from the center of a lazy Susan of negligible mass. The wheel has an angular velocity of 1.0 rev/s. How will the angular velocity of the lazy Susan change if the hamster walks to 0.30 m from the center of rotation? Assume zero friction and no external ...

**11 grade / physics**

a body reaches the max height of 80m when projected at the angle of 30degree find the horizontal component

**physics newton**

During an episode of turbulence in an airplane you feel 180 N heavier than usual. Part A If your mass is 86 kg, what are the magnitude and direction of the airplane’s acceleration?

**physics help**

A 1.2-kg block slides on a horizontal surface with a speed of v=0.80m/s and an acceleration of magnitude a=3.2m/s2, as shown in (Figure 1) . a<__________ box _________>v What is the coefficient of kinetic friction between the block and the surface? Express your answer to...

**physics**

A 9.8-kg monkey hangs from a rope, as shown in (Figure 1) . The tension on the left side of the rope is T1 and the tension on the right side is T2. In the figure, θ=15∘ and ϕ=23∘. Determine the tension T1. Express your answer to two significant figures and include ...

**physics**

a photon whose energy equals the rest energy of the compton collision with an electron, if the electron moves off an angle of 40 degrees to the original photon direction, what is the energy of the scattered photon? assume all constant given. please i need an answer.

**physics**

During an episode of turbulence in an airplane you feel 180 N heavier than usual. Part A If your mass is 86 kg, what are the magnitude and direction of the airplane’s acceleration? 2sf

**Physics ( oscillations and waves)**

a stretched string is observed to vibrate with frequency 30Hz in its fundamental mode when the supports are 60cm apart. the amplitude at the antinode is 3cm.the string has a mass of 30kg.calculate the speed

**physics!**

A (10.25) kg bowling ball is hung on a (11.50) m long rope. It is then pulled back until the rope makes an angle of (39.0)o with the vertical and released. Find the tension in the rope when the ball is at the lowest point. Give your answer in N and with 3 significant figures.

**Physics ( oscillations and waves)**

two collinear harmonic oscillations are X1= 8 sin( 100pi *t) and X2= 12 sin(96 pi *t) are superposed. calculate the values of time when the amplitude of the resultant oscillation will be maximum and minimum

**Physics**

A thin-walled sphere rolls along the floor. What is the ratio of its translational kinetic energy to its rotational kinetic energy through its center of mass?

**Physics**

A 5g bullet is fired horizontally and hits an 8kg block of wood (initially at rest) which can move freely. The wood and the bullet move with a velocity of 0.50 m/s after impact. What is the initial velocity of the bullet?

**Physics**

A 5 gram bullet is fired horizontally and hits an 8 kilogram block of wood (initially at rest) which can move freely. The wood and the bullet move with a velocity of 0.50 m/s after impact. What is the initial velocity of the bullet?

**physics**

a point mass of 12.5 kg is hung from an 18.3 m long rope and swings back and forth with an amplitude of 2.34m. what is the oscillation period for the pendulum system?

**physics**

How much energy is absorbed when 10g of ice at 0degree Celsius becomes steam at 100 degree Celsius?

**PHYSICS**

can someone help me with physics lab homework please: load 300 g at 60 degree mass at 180 deg 150 g mass at 270 deg 260 g for step two resolution of 300-g at 60 degree f load= fx'= fy'= percent error for each component for setup II? WOULD THE HYPOTHETICAL SITUATION DESCRIBED ...

**physics**

can someone help me with physics lab homework please: load 300 g at 60 degree mass at 180 deg 150 g mass at 270 deg 260 g for step two resolution of 300-g at 60 degree f load= fx'= fy'=

**AP physics**

i am given strings at different angle connected to a sign that is at equilibrium. i am given the mass of the sign but only one of the angles of the string. how do i find the tension in each string?

**physics**

The spring is compressed against the floor a distance of 1.6 cm and released. If the spring constant is 60 N/m, what is the magnitude of the spring force acting on the toy at the moment it is released?physics

**physics**

In an arcade game, a 0.12 kg disk is shot across a frictionless horizontal surface by being compressed against a spring and then released. If the spring has a spring constant of 230 N/m and is compressed from its equilibrium position by 8.0 cm, what is the magnitude of the ...

**Physics**

A thin-walled sphere rolls along the floor. What is the ratio of its translational kinetic energy to its rotational kinetic energy through its center of mass?

**physics**

Explain in a few words why, when operating a garden hose fitted with a trigger-operated nozzle, the water jet is momentarily more powerful at the instant the trigger is squeezed than later, when there is a continuous stream of water. Show that the amount of power in the water ...

**Physics**

The figure below represents a section of a circular conductor of nonuniform diameter carrying a current of 4.50 A. The radius of cross-section A1 is 0.300 cm. (a)What is the magnitude of the current density across A1? A: 1.59155e2 using J=I/((r^2)pi) (b) If the current density...

**Physics**

Three charges lie along the x axis the positive charge Q1 = 4mC is at X=2m and the postion of postive Q2 = 8uC is at the origin Q3 is placed on the x axis what is the sign on Q3 and why

**Physics**

Three resistance of 8,12, and 24 ohms are in parallel. This combination is in series with another parallel of 10,10, and 20 ohms. The whole combination is then connected to a battery of 16.6 volts. If the current through the 20 ohm resistor is 0.4 amperes. Find: a.) The ...

**Physics**

One guideline for how diffraction affects shadows is that distinct shadows are created if the width of something is a minimum of 10 times greater than the wave’s wavelength. What would be the narrowest width of something to make a distinct shadow with blue light of frequency...

**Elastic Collisions-Physics**

A 0.16 kg billiard ball moving at 1.20 m/s collides elastically with one of the same mass at rest. It continues at a speed of 0.6 m/s afterward in a different direction from before. What is the final speed of the other billiard ball? I thought it was 0.6 m/s but it says I am ...

**Physics**

The figure is just mass A on top of mass B. There are no forces or anything shown. Block A, of mass 3.2 kg, is on block B, of mass 7 kg, as shown in the above figure. The lower block is on a frictionless surface while the coefficient of static friction is 0.25 between the two ...

**Physics**

A 0.145 kg baseball is thrown at a launch angle of 30° and strikes the ground at 18 m/s. How fast would it be moving when it reaches the ground if it's launch angle were 45°? Ignore air resistance. A. 340 m/s B. 210 m/s C. 16 m/s D. 18 m/s

**Physics**

An anti-aircraft gun fires at an elevation of 60 degree at an enemy aircraft at 10000m above the ground. At what speed must the cannon be shot to hit the plane at that height? (g=9.8)

**Physics**

A solid weighs 4.8g in air, 2.8g in water and 3.2g in kerosene. Calculate the ratio of the density of the solid to that of kerosene

**Physics**

Six points masses each of mass m are placed at the vertices of regular hexagonal of side l , the forces acting on any of the masses is?

**Physics**

the speed of a train increases from 15 mi/h in a distance of 500 ft. calculate the average acceleration in ft/s squared

**physics**

why does water show abnormal behaviour?

**physics**

A cricket ball travelling north at 100km/h is deflected so that it travels north-east at 100km/h. What is the change in velocity of the cricket ball?

**physics**

A cricket ball travelling north at 100km/h is deflected so that it travels north-east at 100km/h. What is the change in velocity of the cricket ball?

**Math / Physics**

A block P of mass 3.56 kg is lying on a rough inclined plane of angle θ = 0.73 radians. Block P is attached via a model string that passes over a model pulley to a second block Q of unknown mass M kg hanging vertically as shown in diagram. The coefficient of static friction ...

**Physics**

A cooking pot contains 0.8kg of water at 100degree celcius what is the specific heat

**Physics**

HBO is concerned about injuries on the set of their award winning fantasy series Game of Thrones. Star characters are given real swords which have a point of balance (centre of mass) 5.0cm above the top of the handle. For safety reasons, you are given only the 15cm long, 0....

**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!**

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 pilot flies his plain in a vertical loop with a radius of 500m. a) what is the speed of the aircraft if the pilot is 'weightless' at the top of the loop? b)what is the weight of the pilot at the bottom of the loop if speed is the same and the pilot is 80kg?

**Physics**

Two perpendicular forces have a resultant of 13N.if one of the forces is 5N, the other force is?