# Homework Help: Science: Physics

## Recent Homework Questions About Physics

**Physics**

A force of 123 N acts on a 10.0kg object for 45.6 meters. If the objects starts at rest, and the surface is flat and frictionless, how fast is the object moving after the force is removed. I got acceleration to be 12.3, but I am not sure how to move on with the problem.

**Physics**

If sound travels at 330m/s in air, how long does it take for sound to travel 10,000m in air? If sound travels at 1500m/s in water, how long does it take for sound to travel 10,000m in water?

**Physics C: Mechanics**

A 1.00 kg mass is attached to a string wrapped around a cylinder of radius 0.05m. Two masses are connected with a rod and attached to the end of the cylinder, perpendicular to its axis. as the mass falls from rest the rotating contraption spins through 12 pi radians in 1.2 ...

**Physics C: Mechanics**

A hollow, thin-walled cylinder and a solid sphere start from rest and roll without slipping down an inclined plane of length 5.0 m. The cylinder arrives at the bottom of the plane 2.6 s after the sphere. Determine the angle between the inclined plane and the horizontal.

**physics**

a metal bar 70cm long and 4.00 kg in mass supported on two knief -edge placed 10 cm from each end. a 6.00 kg weight is suspended at 30 cm from one end . find the reaction at the knife-edge ?

**Physics**

A child pushes a wagon with a passenger of total mass 42 kg along a horizontal surface as fast as the child can run, and then releases the wagon, which continues for another 16 m before stopping. The coefficient of kinetic friction acting to slow the wagon is 0.18. What was ...

**Physics**

A 125-g arrow is shot vertically upward with an initial speed of 28 m/s. Assuming 30% loss in total mechanical energy while ascending, what maximum height above the position from which it was shot does the arrow reach?

**physics**

What is the kinetic energy gained by a 500kg car accelerating from rest to 27m/s? 1/2=mv^2 > 1/2(500)(27m/s)^2= 182,250J a. What is the power output in watts of the engine that causes this acceleration in 4.00s? 27m/s*4s= 108m/s^2 1/2(500)(108)= 27,000 Watts b. How many ...

**PHYSICS**

Heat transfer Q and work done W are always energy in transit, whereas internal energy E is energy stored in a system. Give an example of each type of energy, and state specifically how it is either in transit or resides in a system.

**Physics**

Imagine you are driving a car up Pike’s Peak in Colorado. To raise a car weighing 1000 kilograms a distance of 100 meters would require about a million joules. You could raise a car 12.5 kilometers with the energy in a gallon of gas (if all stored chemical energy was ...

**physics**

Rain drops do not accelerate for long terminal speed due to the vicious drag of the air.if this did not happen rain drop would hit us with a dangerous high speed.discuss

**Physics - Energy**

An airplane is flying with a speed of 250km/h at a height of 3610m above the ground. A parachutist whose mass is 75.2kg, jumps out of the airplane, opens the parachute and then lands on the ground with a speed of 3.75m/s . How much energy was dissipated on the parachute by the...

**physics**

a uniform wooden beam 10 m long ang weighting 200 N is used to support a load of 300 N on the left end , and 500 N on the right end. Determine the center of the gravity if another load of 80 N is 2 m from the left end

**PHYSICS**

To pull a car out of a ditch, one end of the rope POR is tied around a pillar at P and the other end is tied to the car at R. A force of 100N is applied to the Center O of the rope and perpendicular to PR. find the tensions in the rope if the angle POR = 150 degrees

**Physics**

A car is traveling at 7.0 m/s when the driver applies the brakes. The car moves 1.5 m before it comes to a complete stop. If the car had been moving at 14 m/s, how far would it have continued to move after the brakes were applied? Assume the braking force in both cases is ...

**Physics**

If a racehorse starts from rest and accelerates at a rate of 4.7 m/s2, how long does it take the horse to go 20 m?

**Physics - Buoyant Force Question**

Find the buoyant force on a helium balloon in air (Standard Pressure and Temperature) if the balloon is spherical with diameter 12.0 cm.

**Physics - Angular Speed Question**

A merry-go-round can be modeled as a disk with radius 2.5 meters and mass of 150 kg. For this problem, assume the density is uniform. It is initially rotating at 2.0 rad/sec. Two children of mass 30 kg and 40 kg hop onto the merry-go-round and stay near the edge. What is the ...

**Physics Question**

Find the escape speed from (a) the Sun, (b) a white dwarf star with one solar mass (same as the Sun) and radius 10,000 km, (c) a neutron star of 2.0 solar masses and radius of 10.0 km, and finally (d) a star with 2 solar masses and radius 5930 m. Comment on the speed of part (d).

**Physics - Tension Question**

A uniform bar of mass 12 kg and length 1.4 m is held by a hinge on a vertical wall. A string is attached to the end so that the bar is in mechanical equilibrium. The angle between the bar and the string is 25o. Find the tension in the string.

**Physics**

A child on a swing is traveling at 2 m/s as she passes through the lowest part of swing’s arc. What is the period of the motion?

**Physics**

What is the ratio of the volumes for two black holes whose masses are 20 and 10 times the mass of the Sun, respectively? Assume the ’event horizon’ deﬁnes the edge of each black hole’s ’volume’

**Physics**

if the area of cross section of a wire in a circuit is doubled its resistivity? (a)becomes one fourth,(b) becomes half (c) remains the same (d) doubles. Exlpain please?

**Physics**

A hamster is pushed off a cliff by wind. Its mass is 0.040 kg and has a Potential Energy of 98 J. Find the kinetic energy...

**Physics**

A hamster is pushed off a cliff by wind. Its mass is 0.040 kg and has a Potential Energy of 98 J. Find the kinetic energy.

**Physics**

A typical candy bar contains 300 kilo-calories of energy. if all the energy released by eating the candy bar could be used to do work in lifting a 1000 kg car, how high could it be lifted?

**Physics**

A motor takes 5 s to go from 30 rad/s to 130 rad/s at constant angular acceleration. The total angle through which its shaft turns during this time is... A. 400 rad B. 320 rad C. 640 rad D. 800 rad E. 1600 rad F. None of the above

**Physics**

The orbital period of the moon about the earth is approximately 27.3 days. given that the average earth-moon distance is 384,000 kilometers, predict the moon's speed using the expression for centripetal force and the gravitational force, setting them equal to each other.

**Physics**

Use the Law of conservation of energy to predict the final speed of a bowling ball dropped from the top of a 25.0 m tall building just before hitting the ground. ignore air resistance.

**Physics**

Consider two fly wheels labeled A and B both of which are spinning with the same angular velocity. Each flywheel consists of two small heavy spheres connected by very light rods to a light axis. Flywheel A has spheres of mass 2m, each a distance R from the axis. Flywheel B has...

**Physics**

A bar of length 2L can rotate about a frictionless axle at its center. The bar is initially at rest and is then acted on by the three forces shown. What is the magnitude of the net torque on the bar?

**Physics**

a pendulum of length (L) = 1m swings through an angle 20 deg. What is the length (d) of the path traveled by the pendulum mass?

**Physics**

An astronaut throws a ball with mass m to the right with speed v. It strikes the wall of the space station and rebounds, moving left with a speed V/2. What was the magnitude of the impulse of the ball caused by the collision?

**Physics**

In DESPERATE NEED OF HELP!!! An object of mass m = 10 kg and speed v = 2 m/s collides head on with a second object of mass m = 5 kg which has a speed v = 1 m/s. The objects stick together. There are no external forces on the two objects (note the given "v"s are the speeds, not...

**Physics**

an astronaut throws a ball with mass m to the right with speed v. It strikes the wall of the space station and rebounds, moving left with a speed V/2. What was te magnitude of the impulse of the ball caused by the collision? Any help would be greatly appreciated

**Physics**

A pair of objects with masses 3m and m are connected by a hook and have a massless compressed spring between them. Initially the objects are at rest. Then the hook unlatches, the spring expands to its released length and the larger mass is then found moving left with speed v. ...

**Physics**

An object consists of 5 masses, each of mass m, connected by massless rods. The two short rods have length L and the two long rods have length 2L. What is the moment of inertia about an axis perpendicular to the diagram (out of the page) and through the mass labeled x (the ...

**Physics**

A mass m = 1 kg initially at rest at height h = 2m slides to the bottom of a 45 ramp. there is no friction between the mass and the ramp. At the bottom of the ramp the speed of the mass is 4 m/s. How much heat was generated by the friction as the mass slides down the ramp? Any...

**Physics**

A motor lifts an elevator of mass m at constant speed. The power output of the motor is P and there are no frictional losses so that all the power output from the motor goes into lifting the elevator mass. What is the correct expression for the time required for the motor to ...

**Physics**

Searches related to a motor lifts an elevator of mass m at constant speed. The power output of the motor is P and there are no frictional losses so that all the power output from the motor goes into lifting the elevator mass. What is the correct expression for the time ...

**Physics science**

A 10 ohm, 20 ohm lamp and 12v battery are connected in a parallel. A current of 1.8 A passes through the battery and a current of 1.2 A passes through the motor. 1) Determine the current through the lamp. 2) Calculate the potential difference across the motor. 3) is this the ...

**Physics**

An snowboard manufacturer wants to make the smoothest boards ever, she believes that can be achieved by reducing friction as much as possible. Describe 3 things that could be change on a board so that friction between it and the ice gets smaller.

**Physics**

you pull your 6kg dog on a sled which has a mass of 15kg. while you are pulling at 33N, there is a 12N frictional force that is encountered. what is the acceleration of your sled and dog?

**physics multiple choice MCQ 7- i need help please @all respective sir & bro**

the unit of energy in S.I units is? a. watt b. joule c. joule/s d. joule/m e. joule m

**physics multiple choice MCQ 5- i need help please @all respective sir & bro**

The unit of time in S.I. units is? a. second b. minute c. hour d. day e. year

**physics multiple choice MCQ 3- i need help please @all respective sir & bro**

q3= The unit of temperature in S.I units is? a. Centigrade b. Celsius c. Fahrenheit d. kelvin e. Rankin

**physics multiple choice MCQ 2- i need help please @all respective sir & bro**

which of the following laws is applicable for the behavior of a perfect gas? a. Boyle's law b. Charles' low c. Gay-Lussac law d. all of the above e. joule's law

**physics multiple choice MCQ 1- i need help please @all respective sir & bro**

which of the following variable controls the physical properties of a perfect gas? a. pressure b. temperature c. volume d. all of the above e. atomic mass

**physics**

A ball is thrown vertically upwards from ground level hits the ground after 4secs, calculate the maximum hieght it reached during its journey.

**Physics**

query=a stone of mass 30grams is placed in a measuring cylinder containing some water. the reading of the water level increases from 50cm cubic to 60cm cubic. what is the density of the stone?

**Physics**

A simple Atwood’s machine uses a massless pulley and two masses m1 and m2. Starting from rest, the speed of the two masses is 8.2 m/s at the end of 2.2 s. At that time, the kinetic energy of the system is 30 J and each mass has moved a distance of 9.02 m. Find the value of ...

**physics 1**

Q4= The unit of mass in S.I. unit is? a. kilogram b. gram c. tonne d. quintal e. newton

**physics**

A loop of surface area s1=10cm^2 placed ina uniform magnetic field Bof magnitude B1=8×10^-2T, has its plane perpendicular to the field lines . A second loop of area s2=15cm^2 is placed in another uniform field B2 of magnitude B2=0.1T such that its normal unit vector n makes ...

**physics**

a car travels at 25m/s on a slick road takes 4 second to come to a complete stop. what was the car's average acceleration over 4 second?

**Physics**

2. When traveling down the road at a constant speed of 55 mph, 26.4 m/s, the tangential velocity of the wheels is also 55 mph. If a car tire is 65.0 cm in diameter, then; a. What is the period and frequency of the spinning car tire? b. What is the centripetal acceleration of a...

**Physics**

A 2.5m long string vibrates as a 100 Hz standing wave with nodes at 1m and 1.5m from one end of the string and no points in between the two.Which harmonic is this?work out

**Physics**

A jet plane traveling 1890 km/h (525 m/s ) pulls out of a dive by moving in an arc of radius 5.20 km What is the plane's acceleration in g's?

**Physics**

Two parallel straight wires are 1 meter apart. Each wire carries a current of 2 Amperes in the same direction. What is the resultant magnetic field produced by both wires at a point: 2) 1/4 of the distance between them I don't really understand what 2 is saying to be real ...

**Physics**

Blocks with masses of 1 kilogram, kilogram, and 3 kilogram are lined up in a row on a frictionless table. All three are pushed forward by a 12 Newton Force applied to the 1 kilogram block. Draw a free body diagram of all 3 blocks. How much force does the 2 kilogram block ...

**Physics**

A brave but inadequate rugby player is being pushed backward by an opposing player who was exerting a force of 800 Newtons on him. The mass of the losing player plus the equipment is 90 kilograms and he is accelerating at 1.2 meters per second backward. How would I sketch the ...

**Physics**

A raft is made of 15 logs lashed together. Each is 30.0 cm in diameter and has a length of 7.00 m. How many people (whole number) can the raft hold before they start getting their feet wet, assuming the average person has a mass of 66.0 kg? Do not neglect the weight of the ...

**Physics**

A 1500 kilogram car skids to a hold on a wet road where the coefficient of kinetic friction is 0.5. How fast was the car traveling if it leaves 65 meter long skid marks?

**Physics**

For the object in the preceding problem, what magnitude torque is necessary to give the object an angular acceleration of 1.5 rad/s^2 a) along the x-axis? b) along the y-axis? c) along the z-axis (perpendicular to the page, passing through the origin)? Help please! Use the ...

**Physics**

A clock has a second hand which rubs against the inside of the glass cover. If the frictional force between the glass cover and the tip of the hand is 0.0020 N and the length of the hand is 8 cm, what minimum torque must be supplied to the hand by the clock mechanism if the ...

**Physics**

A certain number of identical resistors are connected in series and their total resistance is measured. When the resistors are disconnected and re-connected in parallel, their total resistance drops to one-percent of the value measured when they were connected in series. How ...

**physics**

Blood flows in an aorta of radius 4.12mm at 35.0cm/s. Calculate the volume flow rate. Although the cross-sectional area of a capillary is much smaller than that of the aorta, there are many capillaries, so their total cross-sectional area is much larger. If all the blood from ...

**physics**

a car with a mass of 1.50 x 10^3 kg starts from rest and acceleration to a speed of 18.0 m/s in 12.0 s. Assume that the force of resistance remains constant at 400.0 N during this time. What is the average power developed by the cars engine

**Physics**

Water at a pressure of 4.20 atm at street level flows into an office building at a speed of 0.65 m/s through a pipe 6.60 cm in diameter. The pipes taper down to 2.20 cm in diameter by the top floor, 28.0 m above. Calculate the water pressure in such a pipe on the top floor in ...

**Physics**

A tennis ball is thrown with a velocity of 30m/s at an angle of 60^ of the horizontal calculate the time,m/s,and the range

**physics!!!!**

There is a two member dog sled team pulling with all their strength in the middle of a snow storm. Dog A is pulling with a force of 178 N at 15ð‘œ and Dog B is pulling with 225 N at âˆ’10ð‘œ . The sled and gear weigh 980 N and has a coefficient of friction of 0...

**Physics**

A quarterback throws a spiral to a receiver that is 40m away. The football has a spin of 14 rev/s and went through 58 revolutions before being caught. if the ball is caught at the same height it was thrown at, at what velocity and at what angle should the quarterback throw the...

**Physics**

two charges of 40 microc and -20 micro c are placed at a certain distance apart. they are touched and kept at the same distance.the ratio of their initial to the final force between them is

**physics 101**

You drive your car at a speed 40km/h for 1 hour, then slow down to 30km/h for the next 20km. How far did you drive, and what was your average speed?

**Physics**

A bullet fired in a horizontal direction with muzzle velocity 300m/s. In the absence of air resistance, a) how far will it have dropped in travelling a distance of 20m. b) how far will it have dropped in one second

**Physics**

Hooke's law states that the distance, d, a string is stretched varies directly with the force, F, applied to the spring. If a force of 12 pounds stretches a spring 3 inches, how far will the spring stretch when a force of 30 pounds is applied?

**physics**

A 400-gram package lying on a horizontal surface is attached to a horizontal string which passes over a smooth pulley. When a mass of 200 grams is attached to the other end of the string, the package is on the point of moving. Find the coefficient of friction.

**Physics**

How much energy W needed to compress a spring from 15 cm to 10 cm if the constant of the spring is 150 N/m.

**physics**

A 5kg box on a horizontal table is pushed by a horizontal force of 15N. If the coefficient of friction is 0.4, will the box move? what is the smallest force that could make the box slide along the table?

**Physics: Centre of Mass**

Three masses of 4.0 kg, 5.0 kg and 7.0 kg are located on a line at positions +4.0, +8.0, and -5.0 in meters from the origin, respectively. Where is the center of mass of these three masses? With respect to the origin as x = 0, I calculated the center of mass to be: (4.0 kg)*(4...

**PHYSICS**

A 15 M LENGTH OF HOSE IS WOUND AROUND A REEL WHICH IS INITIALLY AT REST. THE MOMENT OF INERTIA OF THE REEL OF 0.44KGM^2 AND ITS RADIUS IS 0.160M. WHEN THE REEL IS TURNING FRICTION AT THE AXLE EXERTS A TORQUE OF MAGNITUDE 3.40NM ON THE REEL. IF THE HOSE IS PULLED SO THAT THE ...

**PHYSICS**

A PERSON LOWERS A BUCKET INTO A WELL BY TURNING THE HAND CRANK. THE CRANK HANDLE MOVES WITH A CONSTANT TANGENTIAL SPEED OF 120M/S ON ITS CIRCULAR PATH. THE ROPE HOLDING THE BUCKET UNWINDS WITH OUT SLIPPING ON THE BARREL OF THE CRANK. FIND THE LINEAR SPEED WITH WHICH THE BUCKET...

**physics**

a 5kg box is pulled along the floor by a rope that makes a 25 degree angle with the horizontal. the coefficient of kinetic friction between the box and the floor is 0.25. If the box accelerates at a rate of 1.5 m/s squared, what must be the tension of the rope?

**PHYSICS**

AN AUTOMOBILE TIRE HAS A RADIUS OF 0.330M AND ITS CENTER MOVES FORWARD WITH A LINEAR SPEED OF V= 15.0M/S. a) DETERMINE THE ANGULAR SPEED OF THE WHEEL. B) RELATIVE TO THE AXLE, WHAT IS THE TANGENTIAL SPEED OF A POINT LOCATED 0.175M FROM THE AXLE?

**physics**

A MAN HOLDS A 178 N BALL IN HIS HAND, WITH THE FOREARM HORIZONTAL. HE CAN SUPPORT HE BALL IN THIS POSITION BECAUSE OF THE FLEXOR MUSCLE FORCE, M, WHICH IS APPLIED PERPENDICULAR TO THE FOREARM. THE FOREARM WEIGHS 22 N AND HAS A CENTER GRAVITY. FIND THE MAGNITUDE OF M AND B)THE ...

**Physics**

A solid sphere and a thin walled spherical she'll, both with a radius R, are set up to roll down a ramp and through a vertical loop of radius r. From what minimum height, h, does each sphere need to be released in order to make it around the loop? If the loop has a radius of r...

**Physics**

How long will it take a motor with an output power of 4000 W to lift a 250 kg container vertically upwards 25 m? how would u do the calculation?

**Physics**

An object initially rotating at an angular speed of 1.6 rad/sec turns through 30 revolutions during the time it experienced an angular acceleration of 0.32 rad/s^2 a) For how much time did the acceleration last? b) What was the final angular speed? Help please. Use the ...

**Conceptual Physics**

While driving down an icy road in his pickup truck, Dan slid off the road into a ditch. He and his two friends each exerted a force of 200 N on the truck for two minutes, but failed to move it. The work done by the three friends on the truck was? the answer is 3.0m/s but isn't...

**Physics**

An object initially rotating at an angular speed of 1.6 rad/sec turns through 30 revolutions during the time it experienced an angular acceleration of 0.32 rad/s^2 a) For how much time did the acceleration last? b) What was the final angular speed? Help please. Use the ...

**Physics**

what is the angular speed of the earth as it orbits the sun a) in radians/second? b) in degrees per day? I need help please. Use the equation and step by step to get the answer

**Physics**

a softball batter hits a fly ball that is caught 3.8 seconds later, 88m from home plate. The ball is caught at the same height from which it was thrown. What was its initial velocity? What is the maximum height above its launch point that it reached?

**physics**

A centreate block mass 25kg is placed on a wooden plant inclined at an angle 32 dergree to the horizontal calculate the force parallel to the inclined plane that would keep the block rest .If the cofficient of fricition between the block and the plane is 0.45

**Physics**

An engine of car of power 40KW moves on a rough road wit a velocity of 50ms-1.cal.the force require to bring it to rest.

**Physics**

I am trying to help my daughter with this question and don't know how to even begin it. Thank you. A 75 kg baby carriage is pushed along a level sidewalk by exerting a force of 50 N on the handle, which makes an angle of 60o with the horizontal. What is the coefficient of ...

**physics**

a compound microscope has an eyepiece of focal length 10 c.m and an objective of focal length 4c.m.the magnification of an object is placed at a distance of 5 c.m from the objective so that the final image is formed at the distance of distinct vision (20 c.m) is

**Physics**

The cylindrical driving bell whose length is 1.5m is lowered to the bottom of a tank.assume the atmospheric pressure at the surface as equivalent to 1000 cm of water and the temperature as constant

**Physics**

A 24.5-kg sled is being pulled across a horizontal surface at a constant velocity. The pulling force has a magnitude of 87.5 N and is directed at an angle of 30.0° above the horizontal. Determine the coefficient of kinetic friction. µk=

**Physics**

Determine the radius R of an object undergoing circular motion at a velocity of 54 m/s with an acceleration of 90 m/s^2

**Physics**

I don't know how to solve this problem. In it, I am given the mass (4 kg), acceleration (0), velocity (20 m/s), coefficient of friction (.2), and the applied force (10 N downwards with an angle of 30 degrees above the horizontal). I must find the displacement of the object if ...

**Physics**

Calculate the velocity of an object moving around a 32m circle in a period of 11s. Calculate the acceleration.