# Homework Help: Science: Physics

## Recent Homework Questions About Physics

**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**

An ocean liner going from San Francisco to Tokyo stops for a few days in Honolulu you are on board and wish to stamate the time it will take you to get to Tokyo.It is 3700km from San Francisco to Honolulu and 6200km from Honolulu to Tokyo.It took 5.1days to reach Honolulu from...

**physics**

A bullet is fired in to s wall losses half of its velocity after penetrsting 3m.how much further will it penetrate.

**physics**

A rotating platform is on a table and an object is on the platform. The platform has a diameter of 30.0cm and it has a string wrapped around it. The string is threaded over a pulley ( which is right next to the platform and attached to the edge of the table ) . The pulley also...

**physics**

A ball is dropped from a cliff and 2 seconds later, a second ball is thrown vertically downward. What must be the initial velocity of the second ball if it overtakes the first ball as it passes 400m ?

**physics**

a body is thrown vertically upward fron a certain height of pole and their velocity is 100m/s and then it returns to the ground in 6second then find the height of the pole ?

**Physics**

A runner hopes to complete the 10000-m run in less than 30min. After running at constant speed for exactly 27min, there are still 1200m to go. The runner must then accelerate at 0.20m/s^2 for how many seconds in order to achieve the desired time?

**Physics**

Consider the figure above consisting of three particles of mass m attached to a massless rod. Given an axis of rotation through point P, the rod rotates as shown in the figure. If the rod is released from rest in the horizontal position at t = 0. What is the angular ...

**Physics**

A second's pendulum is taken on the surface of moon where acceleration due to gravity is 1/6th of that of earth.Will the time period of pendulum remain same or increase or decrease?Give a reason.

**physics**

A circular round disc that has a radius of 5cm and a mass of 32g is rotating with an angular velocity of w. A second disc with the same radius but with half of the mass is dropped onto the rotating disc . The two discs slide against eachother till they both have the same final...

**Physics**

An elevator weighing 400kg is to be lifted up at a constant velocity of 0.6m/s for this purpose a motor of required horse power is used. (g=9.8m/s).(a)What is the acceleration of motor in case of upward motion? (b)What is power of motor?

**Physics - Forces in Equilibrium**

A beam BC and a cable AB support a weight of 1200lbs. The beam weighs 300lbs. Calculate the tensions in the cable and the reactions of the support C; where A = 30° and C = 45°

**Physics**

A single sphere of water is created by joining 1000 of water spheres of radius r and charge (+Q).If the potential of the small and big spheres are w and v respectively, find v/w. My thoughts : The masses of the spheres are proportional to the third power of there radius. So ...

**Physics**

Why doesn't a magnetic force ALWAYS act on a particle which moves in a magnetic field?

**physics**

A pitcher can throw a ball towards the home plate at 120km per hour. When thrown, the ball curves. The curveball has a spin of 1250rpm. The ball has a mass of 100g and a radius of 2.5cm Calculate the percentage of total KE that is in rotational KE

**physics**

A car wheel has a moment of inertia of 0.35kg m^2. It takes 50 seconds to come to rest from the initial angular velocity of 45 rpm. Calculate the magnitude of the average friction torque

**Physics**

An athlete finished the 100 meter race in 10sec. What was his average speed? acceleration? Acceleration time? Acceleration distance Help with few questions already got the already got the first two V=d/t =100m/10s =10m/s and Acceleration= Vf-Vi/t =10m/s-0/10s =10m/s^2 how to ...

**physics**

what is the acceleration of ball if a ball throw to the wall with velocity of 6m/s and after striking the wall it backs with velocity of 4.4m/s the time for which ball strike the wall is 0.04seconds.

**Physics**

A stream of water emerges horizontally from firehouse at velocity of 15.0 m/s. If the nozzle is 10.0 m above the ground, find a. the time required for the water to reach the ground b. the horizontal distance traveled by the water

**Physics**

Suppose that the lift-drag polar of the previous problem belongs to a 32,000 kilogram aircraft with an average wing chord of 3.5 metres and a wingspan of 30 metres. At a certain moment this aircraft flies in cruise at a speed of 300 ft/s, with an air density of 1.0 kilogram ...

**Physics**

A golf ball of mass 50.0 grams is at rest on a tee. It is struck by a golf club with an average force of 850 Newtons. The ball accelerates to a speed of 68.0 m/sec. How long was the club in contact with the ball?

**Physics**

A 900 W toaster operates for 2.50 minutes. How much energy does it use?

**Physics**

A ball is thrown straight up at 13.0 m/s near the edge of a 30.0-meter high cliff. The ball lands at the bottom of the cliff. a) What is the acceleration of the ball just after it is thrown (magnitude and direction)? b) What is the acceleration of the ball at the peak of its ...

**Physics**

A person runs off a cliff. The person runs with a speed of 10 m/s and is moving to the right as he leaves the cliff. The cliff is 13 meters above a pool of water. a) Determine the acceleration of the person after leaving the cliff (x and y components). b) Determine the time it...

**Physics**

Given the following vectors: A = (28, 110°) B = (63, -30°) Determine A + B. Specify the sum as both Cartesian and polar.

**Physics**

A top fuel dragster can complete a quarter-mile (402 meters) in 4.7 seconds. Assuming that the vehicle starts from rest and that acceleration is constant, calculate (a) the acceleration and (b) the final speed of the top fuel dragster.

**physics**

the distance between 2 towns T1 and T2 is 400km. two cars A and B start simultaneously from T1 and T2 towards each other. the speed of A is 60km/h and that of B is 40km/h the point where two cars will meet is at?

**Physics**

g=4 pi (l/t square)

**Physics**

Steam of 100 degree celsius is passed into ice of 100g . The mixture weighs 120g at 35 degree celsius, find the specific heat of ice.

**physics**

A wheel has an initial velocity of 3.40rad/s and it rotates 1.25 revolutions before stopping what is the angular acceleration of the wheel how long does it take for the wheel to come to rest

**Physics**

You grabbed a power drill that claims it can reach 2234 rpm in 0.8 s. How many revolutions does the drill make in 0.8 s?

**i need sir damon steve reiny and bob physics**

A 100tones acts on a 300tones block placed on an inclined plan with a 3:4 slope, the coefficients of frictions btw the blocks and the inclined plane are 0.25 and 0.20 respectively (A) determine weather the block is in equilibrium ( if the block is not in equilibrium, find the ...

**Physics**

The spin-drier of a washing machine slows down uniformly from 880 rpm (revolutions per minute) to 260 rpm while making 50 revolutions. Find the angular acceleration through these 50 revolutions. Express your answer in rad/s2. The answer is -12.3359871531. I got -13.42.

**Physics**

Fred Flintstone’s club–ax is made up of two parts: an uniform 2.5 kg stick and a symmetrical 10 kg stone attached to the end of the stick. The dimensions of the club-ax are shown in the figure. How far is the center of mass from the handle end of the club-ax? ...

**Physics**

You are tasked with designing a roller coaster ride with a radius of curvature of 6.0 m. What minimum speed must the roller coaster have at the top of the circle so that the passengers experience a sense of "'free fall"?

**physics**

A lump of lead with a mass 0.5kg is dropped from a height of 20m onto a hard surface. It does not rebound but remains there for a long time. A) what is the increase in heat B)what is the increase in internal energy C)what is the increase in temperature

**physics**

horizontal and vertical component of earth's magnetic field at a place are 0.22 tesla and 0.38 tesla respectively then find the resultant intensity of magnetic field

**Physics**

A vector has a magnitude of 3.50m and points in a direction that is 145 degree counter wise from the x-axis. find the x and y components

**Physics**

A ship sails north at 15 km/h but drifts westward with the tide at 8 km/h. What is the resultant velocity of the ship? Help me Please

**Physics**

How long does a car with an acceleration of 2.0m/s2 take to go from 10m/s?

**Physics**

A 30m bar with a mass of 20kg is being lifted by a string. The bar makes an angle of 55 degrees above horizontal (between the bar and ground). The string is attached to the ceiling vertically. What is the tension on the string? What is the normal force given by the bar on the ...

**Physics**

A bar with a mass of 20kg with a length of 30m is being lifted by a string and makes an angle of 55 degrees. The string is attached to the ceiling vertically. What is the tension on the string? What is the normal force given by the bar on the string what is the force of static...

**physics**

A 13.0 gram sample of an unknown metal at 30.0*C is placed in a Styrofoam cup containing 50.0 grams of water at 90.0*C.The water cools down and the metal warms up until thermal equilibrium is achieved at 87.0*C.Assuming all the heat lost by the water is gained by the metal and...

**Math - Physics**

A typhoon moving 165 km/h 300 south of west is caused by two other forces acting in different directions. Find the components of the typhoon’s velocity that is due to the two forces.

**Physics**

On an unwanted weather situation, rescue operators fly a helicopter that is aimed to travel 100 knots due southwest. However, two winds coming from different directions move it sideways. One wind is making it move sideways 20 knots northward while the other makes it move 10 ...

**Physics**

A stone is thrown vertically up word by up word by a boy . It returns to his hands in 3sec . How high does the stone rise ?

**physics**

How many electron can passes through a cross sectional area of a conductor per second

**Physics**

6m due south,10m due east and 5m due north. Find the distance traveled and the displacement of the vector

**physics**

how many 0.25-pF capacitors must be connected in parallel in order to store 1.2uC of charge when connected to a battery providing a potential difference of 10v?

**Physics - Vectors/Forces**

A 10 kg weight is on an inclined plane 10 ft long and 6 ft high. If there is no friction, what force parallel to the plane will prevent the body from sliding?

**Physics**

Find analytically the resultant of the forces shown below: Where: F1 = 20 kg (4,4) F2 = 15 kg (-5,5) F3 = 5 kg (-2,-2) F4 = 10 kg (3,-3)

**Physics**

A pendulum bod weighing 500g is suspended on a fine wire. What is the tension on the wire when the bod swings at 60° from the vertical?

**Physics**

Two cars collide at an icy intersection and stick together afterward. The first car has a mass of 1200 kg and is approaching at 8.00 m/s due south. The second car has a mass of 850 kg and is approaching at 17.0 m/s due west. (a) Calculate the final velocity (magnitude and ...

**physics**

A car is moving at 80km/h is subjected to a uniform retardation and brought to rest in 70seconds.find retardation and distance travelled by the car before it comes to rest.

**physics**

A patient is getting his elbow rehabilitated. He is told to lay his elbow flat on a table and lift a a 3.5kg weight by bending his elbow( he's raising his forearm itself and the weight). The weight is 30cm from his elbow. After telling his therapist that it hurts for him to ...

**Physics**

Jordan is trying to loosen a stuck bolt in his motor home. To loosen it ,he is using a wrench that is 60cm long. If he hangs from the wrench, what is max torque he can exert ? Jordan is 75kg

**College Physics**

The maximum speed of a 4.0-kg mass attached to a spring is 0.70 m/s , and the maximum force exerted on the mass is 12 N . a) What is the amplitude of motion for this mass? b) What is the force constant of the spring?

**Physics**

Show that the average velocity of a particle over an interval over an interval of time is is either is either smaller than and the average speed of the particle over same interval

**physics**

Calculate the mass of brass if the heat to rise it's temperature of 10k is 38000j and it's specific heat capacity Of water is 380j/kg

**College Physics**

A mass m is acted on by a resultant force of 28.6 N in the upward direction. The acceleration of the mass is 5.72 m/sec2 upward. What is the mass?

**College Physics**

A mass of 50.0 kg is acted on by only two forces: Force 1 is 650 N to the right, and Force 2 is 520 N to the left. What is the acceleration of the mass in response to these forces?

**College Physics**

A car of mass 1000 kg is traveling at a constant 25.0 m/sec along a straight, level highway. There is a force of thrust acting on it in the forward direction (the direction the car is moving) of 3000 N. There are drag forces and forces of rolling friction opposing the motion ...

**Physics**

A person of mass 65.0 kg is standing on the floor of an elevator. The elevator is accelerating upward at 1.50 m/sec2. What resultant force acts on the person?

**College Physics**

A person of mass 65.0 kg is standing on the floor of an elevator. The elevator is accelerating upward at 1.50 m/sec2. What does the person weigh?

**College Physics**

A ball is thrown horizontally from the top of a building which is 30.6 meters tall. It lands 50.0 meters from the base of the building. What was the launch speed of the ball?

**College Physics**

A rock is thrown from the top of a cliff. It lands 2.33 seconds later 17.3 meters from the base of the cliff. How far did it drop vertically? What is the speed of the rock when it lands?

**Physics**

Does the speed of sound in air depend on the frequency of the wave? V=[(gamma.RT)/M]^(1/2)

**physics**

A falling stone take 0.2s to fall post a window with. Hight 1m from how far above the top of window stone dropped

**Physics**

a particle moving in the xy plane has velocity components dx/dt =2t and dy/dt = 4. If the particle starts from the origin at t = 0,magnitude of its displacement at t=2 is

**Physics**

A 7150 kg truck traveling east at 5 m/s collides with a 1650 kg car traveling 30 degrees south of west at 20 m/s. After the collision at what angle do the two vehicles move. Express you answer in degrees from the positive x-axis. Use a coordinate where north is the +...

**physics**

what is the minimum work that must be done to raise a 30.0 kg object from h 7.0 m to h=11.0 m?

**Physics**

how much work is needed to raise a 6.0 Kg object14.0 m at constant speed?assume that friction is negligible.

**physics**

A tick is standing on a turntable at distance r from the centre. The static friction coefficient between the tick and table is us. The table is spinning at a constant angular frequency of w a) what values of r is the bug most likely to slip at? small or large ? b) The tick is ...

**Physics**

The hydrostatic equation holds not just for air, but for other fluids such as water (air, though it is a gas, is often referred to as a 'fluid') as well. In the case of water the equation becomes even easier, as water (as opposed to air) can be treated as incompressible, ...

**Physics**

A hemisphere of radius r is placed on a horizontal plane and a small mass of "m" is placed on the top of the hemisphere. Find the height from the ground to the mass m,at the moment it loses it's contact with the hemisphere.And the contact is frictionless. If we take the speed ...

**physics**

a cricket ball is takes 3 sec to reach the maximum height its initial velocity is???

**Physics**

The carbon isotope 14C is used for carbon dating of objects. A 14C nucleus can change into a different kind of element, a neighbor on the periodic table with lower mass, by emitting a beta particle – an electron or positron – plus a neutrino or an anti-neutrino. ...

**physics**

A wheel has an initial speed of 100 radians/s. It is then slowed down with a magnitude of the constant angular acceleration of 6.0s^-2. To make it come to rest, how many revolutions does it need to make?

**College Physics**

An archer draws a bow, getting ready to shoot a 55.0 gram arrow. The tension in the bowstring is 424 N, and it is bent at the angles 30 degrees a)What is the magnitude of the "drawing" force holding the string at rest? b)If the drawing force is removed (by the archer releasing...

**physics**

A plane is in a steep downward plunge. To not crash, Captain Q pulls as much as he can. When the plane is at the lowest point of the plane's path the plane is in a circular arc of radius 450m. Captain Q experiences an acceleration of 5.0g ( so her weight feels like six times ...

**Physics**

A bullet of mass 12g which is fired horizontally hits the wooden block of mass 1kg suspended on a string (a) calculate the initial velocity of the bullet . (b) calculate the energy lost by the bullet when it hits the wooden block

**Physics**

On new year eve,a fire work rocket is launched vertically into the night sky with an initial speed of45m/s .After 2.55s ,the coasting rocket then explode and break into two pieces with an equal mass .Each pieces follow trajectory of 45 degree to the verticle . Find their speed...

**physics**

A plane wave is represented by the equation y=4si(230pit+0.85pix)M. find (a)the frequency (b)velocity and Wave length of the wave

**Physics**

Water flows through a pipe of radius 4 cm at a rate of 3.5 m/s. Suppose each water molecule is singly ionized (highly unrealistic). a) What is the electric current density associated with the flow of these ions? b) What is the electric current in the pipe?

**Physics**

An electric filament can heat 200 cm^3 of water from 5°C to 95°C in 6 minutes. If the voltage source is a 12 V battery, how much current does it draw?

**Physics**

An archer lying on the ground shoots an arrow at a target that is 400 meters away, and 40 meters high. The initial velocity of the arrow is 120 m/s At what angle does he need to point his bow in order to hit the target? (Assume the value of g as -9.81 m/s² ).

**Physics**

A 50-Newton box lays on a plane inclined 20degrees from the ground. Though the weight of the box is directed downwards, we know that some component of it is responsible why the box would slide. Find the value of this component

**college physics**

A hockey puck of mass 0.228 kg si sliding across level ice. There is a force of friction of 0.057 N acting opposite the direction of motion of the puck while it is sliding. a) what is the acceleration of the puck while it is sliding? b)if it initially has a speed of 10.0 m/sec...

**college physics**

A ball rolls off the edge of a level tabletop. It travels 36.5 cm horizontally and falls a vertical distance of 81.9 cm. What is the magnitude and direction of the velocity of the ball at the instant it reaches the floor?

**college physics**

A stone is thrown horizontally from the top of a building with a speed of 29.5 m/sec. It lands 56.3 meters from the base of the building. How long was it in the air, and how tall is the building?

**Physics**

A 6.0 kg mass is pulled horizontally along a level surface where the coefficient of friction is 0.20. The mass accelerates at 0.68 m/s2. a) What is the friction force acting on the mass? b) What applied force is being used to pull the mass?

**physics**

A plane is in a steep downward plunge. To not crash, captain Q pulls as much as he can. When the plane is at the lowest point of the plane's path the plane is in a circular arc of radius 450m. Captain Q experiences an acceleration of 5.0g ( so her weight feels like six times ...

**Physics**

A bullet of mass 6.45 g is fired from a 66.0 cm-long rifle barrel at 237 m/s. The mass of the rifle is 4.50 kg. Determine the acceleration of the bullet as well as the recoil acceleration of the rifle.

**Physics**

A student pushes horizontally on a textbook of mass 0.250 kg and holds it stationary against the classroom wall. a) Draw a free body diagram showing and labeling all the forces acting on the textbook. b) From your diagram, what is the friction force that holds the textbook in...

**Physics 11**

A 140 kg stationary crate is pulled by a force of 390 N along a horizontal surface. a) The coefficient of static friction between crate and surface is s = 0.25. Is the applied force large enough to begin moving the crate? Use physics calculations to prove that it is. b) The...

**physics**

A few children are playing around the carousel at the park. You see that one of them can't hold on to the edge of the carousel ( that has a radius of 2m) when it takes less than 3.0s to do one full revolution. a) what's the acceleration that the kid can manage? b) what would ...

**physics**

A kid places a toy on the outermost edge of a merry go round. The amusement park ride has a radius R and period T. What is the smallest value of us (static friction coefficient) between the toy and merry go round where the toy is able to stay on the ride?

**physics**

A driver A travelling at 54km/hr and stops the car in 4sec.another car B travelling at36km/hr and stops the car in 6sec.Plot speed time graph for two cars.which of the cars travelled farther before stooping?

**physics**

If an object of dimension 40cm×30cm×10cm is floating on a liquid of density 1g/cc.What height of the object will be exposed outside of the water given that the density of object is 0.92g/cc?

**physics**

Robin Hood has to shoot an arrow at an apple that sits on a wall 400 meters away, at a height of 40 meters. He must shoot at an angle of 60 degrees. What must the initial velocity of the arrow be to hit the target? Assume he's shooting laying down on the ground, making the ...