Sunday
May 1, 2016

Homework Help: Science: Physics

Recent Homework Questions About Physics

Physics
An astronaut exploring a distant solar system lands on an unnamed planet with radius 3,860 km. When the astronaut jumps upward with an initial speed of 3.5 m/s, she rises to a height of 0.62 m. What is the mass of the planet to within 0.1%?
Monday, March 21, 2016 by suveer

physics
Soft tissue has a linear attenuation coefficient in the range of μ = 0.35 cm−1 at 30 keV and μ = 0.16 cm−1 at 100 keV. For this problem we use μ = 0.21 cm−1, which applies at around 50 keV incident X-ray energy. (a) What fraction of X-ray ...
Monday, March 21, 2016 by mar

PHYSICS?
1300 kg car rounds a banked curve of radius= 50m. If car traveling at 75 km/h and the coefficient of static friction between the tire and road is 0.45 ... 1.) what is the minimum angle of the bank needed to keep the car in the turn? 2.) If the car changes tires, which ...
Monday, March 21, 2016 by Dina

Physics
With what maximum speed can an unsecured passenger stay in their seat on a Ferris wheel that has a diameter of 12 m.
Monday, March 21, 2016 by Jules

Physics
3)-A 9-kg block is held by a pulley system shown in fig. What force must the person exert in the following cases: a) to hold the block at rest. b) to lower it at 2m/s. c) to raise it with an acceleration of 0.5 m/s2? Ignore the mass of small pulley.
Monday, March 21, 2016 by Simon

PHYSICS HELP
3)-A 9-kg block is held by a pulley system shown in fig. What force must the person exert in the following cases: a) to hold the block at rest. b) to lower it at 2m/s. c) to raise it with an acceleration of 0.5 m/s2? Ignore the mass of small pulley.
Monday, March 21, 2016 by Simon

Physics help pls
Pls help me I have a test tmrw A block with mass 5kg slides along a horizontal floor under the action of a force 20N applied upward at an angle θ to the horizontal. The coefficient of kinetic friction between the block and the floor is μk = 0.4. Find the angle θ...
Monday, March 21, 2016 by Jamila

Physics
A swimmer point directly to the North Shore of a 20.0 m wide river that has a current of 2.7 m/s [W]. If she can swim at 1.3 m/s in water; A. Draw an appropriate diagram for the question B. How long does it take her to cross? C. How far downstream does she land? D. What is her...
Monday, March 21, 2016 by Ceara

Physics
Tom (65 kg) is standing on a scale in an elevator holding an apple. The elevator begins to accelerate downwards at 2.4 m/s2. (a) What does the scale read during this acceleration? (b) What is the acceleration of the apple with respect to Tom holding the apple? 2.4 m/s^2 (same ...
Monday, March 21, 2016 by lost in life

Physics
Jason and Kim are attempting to push a heavy fridge across the kitchen floor. When Jason pushes it with a muscular force of 550. N, the fridge accelerates from rest to 28.0 cm/s in 3.50 s. When Kim pushes it with a muscular force of 560. N, the fridge accelerates from rest to...
Monday, March 21, 2016 by lost in life

Physics
A car is traveling around a bend at a speed of 12.4 m/s. The bend has a radius of curvature of 66.7 m. Friction is the only force acting towards the center of the circle. If the mass of the car is 862 kg, what is the force of friction required to make the car go around the bend?
Monday, March 21, 2016 by Em

Physics
A ball is attached to a center post by a string that is 0.382 m long. The ball is moving in a circle on a frictionless table top at a speed of 1.28 m/s with a radius of 0.382 m. What is the centripetal acceleration of the ball?
Monday, March 21, 2016 by Em

Physics
If the angular velocity, ω, changes from 7.07 rad/s to 24.2 rad/s over a time of 6.42 s, what is the angular acceleration, α?
Monday, March 21, 2016 by Em

physics
A net force of 1.6×10−15 N acts on an electron over a displacement of 7.1 cm, in the same direction as the net force. (a) What is the change in kinetic energy of the electron (joules)?
Monday, March 21, 2016 by amanda

Physics
If a wheel turns around 6.00 complete rotations, what would the angular displacement of that wheel be in radians?
Monday, March 21, 2016 by Em

Physics 101
A storage tank of negligible mass and 30m high is filled with gasoline. What is the force that acts on a square access hatch at the bottom of the tank that measures 0.5m x 0.5m
Monday, March 21, 2016 by Michelle

Physics
A 100 hp motor raises a 200lb elevator 200 ft in 10 sec. The efficiency for the elevator system is 72.7% or 73%. How much energy is lost in 10 sec? Answer: 193 Btu Show work
Monday, March 21, 2016 by Merrick

Physics
We can measure angles in degrees or radians. When studying angular motion, we will tend to use radians. If you are looking at a portion of a circle, the angle in radians can be calculated by dividing the arc length by the radius of the circle. The arc length for a complete ...
Monday, March 21, 2016 by Anonymous

PHYSICS! are these correct?
How much kinetic energy does a 700-gram baseball have that is travelling at 20 m/s? What would be the kinetic energy if you doubled the mass? What would be the kinetic energy if you doubled the velocity? V1= 20 m/s K1= ½ m v1^2 = ½ (700 g)(20 m/s)^2 = ½ (...
Monday, March 21, 2016 by A

physics
A constant electric field is 29, 000N/C is created between two parallel plates. If the potential difference is 140, 000V , how far apart are the two plates?
Monday, March 21, 2016 by kim

physics
Two charges +q and −q are separated by a distance d. Find an expression for the potential difference VBA = VB − VA, where points A and B are both a distance b from the charges. 
Monday, March 21, 2016 by kim

physics
during a collision, a driver of mass m in a car moving at speed v is brought to rest by an inflated air bag in time t. (a) write an equation showing the average force the air bag exerts on the driver. (b) suppose the mass of the driver is 55 kg, the initial speed of the car is...
Monday, March 21, 2016 by osama

Physics helllppp
8] Find the minimum stopping distance for a car moving at 108km/h if the coefficient of static friction between the tires and road is a) 0.9
Monday, March 21, 2016 by Amelie

Physics
Find the minimum stopping distance for a car moving at 108km/h if the coefficient of static friction between the tires and road is 0.9 I really dont understand pls helppp
Monday, March 21, 2016 by Amelie

Physics
A 5 kg block is being pulled on a frictionless surface by a string at an angle of 30o to the horizontal. The tension in the string is 30 N. What is the total work done on the block as it moves a distance of 10 m?
Monday, March 21, 2016 by Danny

Physics
A transparent photographic slide is placed in front of a converging lens with a focal length of 2.41 cm. An image of the slide is formed 13.0 cm from the slide. (a) How far is the lens from the slide if the image is real? (Enter your answers from smallest to largest starting ...
Monday, March 21, 2016 by Deaven

Physics
In a water park, people walk a distance of 20 meters up an inclined ramp before getting on a water slide. If the spot from where they start sliding down is located 7 meters above the water’s surface, calculate the angle of the ramp with the horizontal
Monday, March 21, 2016 by Adrian Watkins

PHYSICS
Kinetic Energy and the Work/Energy Theorem: 1.) How much kinetic energy does a 700-gram baseball have that is travelling at 20 m/s? What would be the kinetic energy if you doubled the mass? What would be the kinetic energy if you doubled the velocity? 3.How much work must ...
Monday, March 21, 2016 by S.A

please help my 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 d/t if he didn't bend his knees and stopped in 0.1s?
Monday, March 21, 2016 by yaekob

physics
A 5 kg block is being pulled on a frictionless surface by a string at an angle of 30o to the horizontal. The tension in the string is 30 N. What is the total work done on the block as it moves a distance of 10 m? Thank you!
Monday, March 21, 2016 by Donna

Physics
A 5kg block is being pulled on a horizontal frictionless surface. The tension in the string is 30N. If the block has an initial speed of 2m/s, what is the speed after moving 10 meters? Please help!Thanks
Monday, March 21, 2016 by Donna

Physics
A stone A is dropped from the top of a very high platform. At the same time another stone is thrown vertically upward from the ground level with an initial speed of 50m/s. At the instance that the stone passes each other, the ration of the velocities of A and B is 2:3 ...
Sunday, March 20, 2016 by Jefferson Mckinley

Physics
Bob (80 kg) lands with a resultant GRF of 1200 N at an angle of 80 degrees from the horizontal. Round answers to nearest whole number. What was his vertical acceleration during landing?
Sunday, March 20, 2016 by Matthew

physics 101
A truck is moving at the speed of 30 miles per hour, what is it's speed in meter per second.
Sunday, March 20, 2016 by Grace

Physics
A 5kg block is being pulled on a horizontal frictionless surface. The tension in the string is 30N. If the block has an initial speed of 2m/s, what is the speed after moving 10 meters? Please help!Thanks
Sunday, March 20, 2016 by Donna

Physics
Draw a FBD of an object that has forces acting on it that are not at right angles. If someone can provide me of some sort of example of what situation could represent this i would appreciate it.
Sunday, March 20, 2016 by Steve

Physics
a bird is flying through the air with an air speed 12.6m/s heading 27.7 west of north. it is a windy day with wind velocity blowing at 8.95m/s heading 12.5 south of west. what is the velocity of the bird as seen by a person on the ground
Sunday, March 20, 2016 by Jen

Physics
your car has stalled and has come to rest on a level section of a busy street. you and a passenger decide to push the car to the side of the road so it will not interfere with the trafic. together you excert a combine horizontal force of 1320N. the coefficent of static ...
Sunday, March 20, 2016 by Jen

physics
A ball of mass 0.50 kg is thrown vertically upwards, calculate the net force on the ball at the top of its flight
Sunday, March 20, 2016 by Duy

physics
Given a slab with refractive index n=1.33 and incident light striking the top horizontal face at angle i.The maximum value of i for which total internal reflection occurs is:
Sunday, March 20, 2016 by Manu

physics
the tires of a certain car begin to lose their grip on the pavement at acceleration of 5 m/s to the power of 2 if the car has this acceleration , how many seconds does it required reaching a speed of 25 m/s starting from 10 m/s?. Please help me
Sunday, March 20, 2016 by shiela vargas

Physics
A 5kg block is being pulled on a horizontal frictionless surface. The tension in the string is 30N. What is the total work done on the block as it moves a distance of 10 meters? Thank you very much!
Sunday, March 20, 2016 by Steve

Physics
An object with Fnet = 0 moving at a constant velocity. FBD Diagram I don't understand how this is possible, if some one could please explain it to me and if possible draw a quick diagram on an external site. (i.e. Sumopaint )
Saturday, March 19, 2016 by Next

11th grade physics
Four identical positive charges q are placed at the four vertices of a square of side a. Determine the electric field: A) at the center of the square B) at the midpoint of one of its sides
Saturday, March 19, 2016 by angy

physics
Four identical positive charges q are placed at the four vertices of a square of side a. Determine the electric field: A) at the center of the square B) at te midpoint of one of its sides
Saturday, March 19, 2016 by angy

Physics
Given m=2.0kg h=2cm
Friday, March 18, 2016 by AME

Physics
A rocket which is 700000kg(given that the rocket never loses mass) working with 10.000.000 Newton, how much is the acceleration? basic question, but i was wondering about the gravitation how would you calculate this.
Friday, March 18, 2016 by Steinar

physics
In preparing to shoot an arrow, an archer pulls a bowstring back 0.49 m by exerting a force that increases uniformly from 0 to 277 N. What is the equivalent spring constant of the bow?
Friday, March 18, 2016 by Lindsey

physics
if the distance between two bodies is increased by 25% then % change in the gravitational force is
Friday, March 18, 2016 by sana

Physics
Suppose the 480 lbs pile driver that drops 20 ft drives the pile 2.0 in. every time it strikes the pile. What is the average resisting force of the ground where the pile is driven? Answer: 57,600 lbs Show Work
Friday, March 18, 2016 by PAT

Physics
A device that can alter the resistance in a circuit is known as a: a. switch b. potentiometer c. circuit breaker d. ammeter
Friday, March 18, 2016 by John

physics
what is the heat capacity of a gold ring that has a mass of 7.00g
Friday, March 18, 2016 by bob

Physics
A 40.0 ohm resistor, 20.0 ohm resistor, and a 10.0 ohm resistor are connected in series across a 220-V supply. Which resistor is the warmest? a. 40.0 ohm b. 20.0 ohm c. 10.0 ohm d. they are all the same
Friday, March 18, 2016 by Joe

Physics
A 25 g bullet with a muzzle velocity of 300 m/s is fired into a board 4.0 cm thick. For a soft board, the bullet goes through the board and emerges with a speed of 50 m/s. What was the average force exerted on the bullet by the board? Answer= 27344 N Show Work
Friday, March 18, 2016 by Andy

Physics
Suppose the 480 lbs pile driver that drops 20 ft drives the pile 2.0 in. every time it strikes the pile. What is the average resisting force of the ground where the pile is driven? Answer: 57,600 lbs Show Work
Friday, March 18, 2016 by Bob

Physics
A 25 g bullet with a muzzle velocity of 300 m/s is fired into a board 4.0 cm thick. For a soft board, the bullet goes through the board and emerges with a speed of 50 m/s. What was the average force exerted on the bullet by the board? Answer= 27344 N Show Work
Friday, March 18, 2016 by Bob

Physics
A 25 g bullet with a muzzle velocity of 300 m/s is fired into a board 4.0 cm thick. A). In a hard board, the bullet penetrates 3.0 cm and comes to a stop. What is the average force exerted on the bullet by the board? B). For a soft board, the bullet goes through the board and ...
Friday, March 18, 2016 by Reed

Physics
Suppose the 480 lb pile driver that drops 20 ft drives the pile 2 in. every time it strikes the pile. What is the average resisting force of the ground where the pile is driven?
Friday, March 18, 2016 by Reed

Physics
A 3200 lb car traveling at 30 mi/hr speeds up to 60 mi/hr. How much useful work was supplied by the engine?
Friday, March 18, 2016 by Reed

Physics
How much work is required to bring a 1000 kg racing car traveling at a speed of 60 km/hr to rest?
Friday, March 18, 2016 by Reed

physics
a person, with his ears to the ground, seconds a huge stone strike the concrete pavement. a moment later two sounds are heard from the impact, one travels in the air and other in the concrete, and they are 0.80 seconds apart. How far away the impact occur?
Friday, March 18, 2016 by Anonymous

Physics HW Plz help
Why can't most objects like an apple travel at speeds above the speed of light?
Friday, March 18, 2016 by Student Lexi

Physics
A 4kg box is attached to a 2.4m rope rotating on platform. Max tension can withstand without breaking is 140N. 1.) Find Max. speed w/ which the box can rotate if the surface of platform is frictionless. 2.) Find Max speed w/ which box can rotate if Coeff. of friction between ...
Thursday, March 17, 2016 by Kelly

physics
A banked circular highway curve is designed for traffic moving at 57 km/h. The radius of the curve is 216 m. Traffic is moving along the highway at 42 km/h on a rainy day. What is the minimum coefficient of friction between tires and road that will allow cars to take the turn ...
Thursday, March 17, 2016 by krals

physics
In the figure, two blocks are connected over a pulley. The mass of block A is 7.9 kg and the coefficient of kinetic friction between A and the incline is 0.18. Angle θ of the incline is 41°. Block A slides down the incline at constant speed. What is the mass of block B?
Thursday, March 17, 2016 by krals

physics
A block of mass m1 = 3.56 kg on a frictionless plane inclined at angle θ = 34.1° is connected by a cord over a massless, frictionless pulley to a second block of mass m2 = 2.72 kg hanging vertically (see the figure). (a) What is the acceleration of the hanging block (...
Thursday, March 17, 2016 by krals

physics
An elevator cab is pulled upward by a cable. The cab and its single occupant have a combined mass of 1980 kg. When that occupant drops a coin, its acceleration relative to the cab is 7.30 m/s2 downward. What is the tension in the cable?
Thursday, March 17, 2016 by krals

physics
At what altitude above Earth's surface would the gravitational acceleration be 1.20 m/s2? (Take the Earth's radius as 6370 km.)
Thursday, March 17, 2016 by krals

College Physics
A student of mass M = 82 kg takes a ride in a frictionless loop-the-loop at an amusement park. The radius of the loop-the-loop is R = 15 m. The force due to the seat on the student at the top of the loop-the-loop is FN = 696 N and is vertically down. What is the apparent ...
Thursday, March 17, 2016 by Jack

math
A physics test has twenty questions worth 100 points. The test consists of true /false questions worth 3 points each and multiple choice questions worth 11 points each. How many multiple choice questions are on the test ?
Thursday, March 17, 2016 by Elizabeth

physics
(a) A concave spherical mirror forms an inverted image different in size from the object by a factor a > 1. The distance between object and image is d. Find the focal length of the mirror. (Use any variable or symbol stated above as necessary.) (b) Suppose the mirror is ...
Thursday, March 17, 2016 by Bisi urgent

physics
Question Part Points Submissions Used A flint glass plate (n = 1.66) rests on the bottom of an aquarium tank. The plate is 6.50 cm thick (vertical dimension) and is covered with a layer of water (n = 1.33) 15.0 cm deep. Calculate the apparent thickness of the plate as viewed ...
Thursday, March 17, 2016 by Anonymous urgent

physics
Two blocks are sliding along a frictionless track. Block A (mass 3.73 kg) is moving to the right at 1.50 m/s. Block B (mass 4.48 kg) is moving to the left at 1.80 m/s. Assume the system to be both Block A and Block B. a) what is the total momentum of the system before the ...
Thursday, March 17, 2016 by Anonymous

Physics
a person falls flat on their back on some slipper ice and is unconscious for a second. the horizontal position of their legs, torso and head from their feet is given by 0.48m, 1.35m and 1.7m respectively and their weights are 30kg, 50kg and 10kg. they try to sit up on the ice ...
Thursday, March 17, 2016 by Anonymous

science(physics)
A 2kg stone is droped from the top of a 20m building a)what potential energy does it posses b)At what height does its potential energy become equal to its kinetic energy? c)what is its kinetic energy just before it hits the ground? d)With what velocity does it reach the ground...
Thursday, March 17, 2016 by joe john

physics
you are trying to balance a tray of dishes to make it easy to carry. at one end of the 0.6m tray are four plates with total mass 0.5 kg with their centres of mass exactly above the left edge of the tray. how far from the left edge should you place 2.1 kg jug of milk so that ...
Thursday, March 17, 2016 by Anonymous

Physics
a 24 gramme bullet travelling at 198m/s buries itself in a 6.5kg pendulum hanging on a 2.2 m length of string, which makes the pendulum swing in an arc. determine the horizontal component of the displacement of the pendulum.
Thursday, March 17, 2016 by Anonymous

Physics
Three wires lie in a plane, placed parallel to one another and equally spaced by 0.20 m. If the wires are oriented up and down on the page, the right-hand wire carries 100 A to the top, the middle wire 300 A to the bottom, and the left-hand wire carries 200 A to the top. What ...
Thursday, March 17, 2016 by Anonymous

physics
A puck of mass m = 1.90 kg slides in a circle of radius r = 16.0 cm on a frictionless table while attached to a hanging cylinder of mass M = 3.70 kg by a cord through a hole in the table. What speed keeps the cylinder at rest?
Thursday, March 17, 2016 by krals

Physics
A very thin, infinitely long metal sheet lies in the xy-plane, between x = -w and x = w. A current of density h A/m flows in the +y-direction. What are the magnitude and direction of the magnetic field at a distance z « w above and below the sheet? Neglect end effects.
Thursday, March 17, 2016 by Anonymous

physics
When the three blocks in the figure are released from rest, they accelerate with a magnitude of 0.900 m/s2. Block 1 has mass M, block 2 has 2M, and block 3 has 2M. What is the coefficient of kinetic friction between block 2 and the table?
Thursday, March 17, 2016 by krals

physics
Suppose the coefficient of static friction between the road and the tires on a car is 0.749 and the car has no negative lift. What speed will put the car on the verge of sliding as it rounds a level curve of 31.7 m radius?
Thursday, March 17, 2016 by Anonymous

Physics help
You are standing directly under an electrical wire carrying current towards the South. If the wire is carrying 180 A and is located 12 m overhead, determine the magnitude and direction of the magnetic field where you are standing. direction of the magnetic field into the page...
Thursday, March 17, 2016 by Matt Damon

Physics
A 68.2 kg person jumps from rest off a 2.90 m-high tower straight down into the water. Neglect air resistance during the descent. She comes to rest 1.06 m under the surface of the water. Determine the magnitude of the average force that the water exerts on the diver. This ...
Wednesday, March 16, 2016 by Anonymous

Physics - Repost because of no response
In an experiment on the shuttle, an electron with a speed of 6.3 x 105 m/s [N] and a mass of 9.11 x 10-31 kg is shot through an external magnetic field. Determine the strength and orientation of the magnetic field required so that the electron's direction of travel remains...
Wednesday, March 16, 2016 by Matt Damon

physics
A basketball player makes a jump shot. The 0.593 kg ball is released at a height of 1.95 m above the floor with a speed of 7.12 m/s. The ball goes through the net 3.10 m above the floor at a speed of 4.08 m/s. What is the work done on the ball by air resistance, a ...
Wednesday, March 16, 2016 by Anonymous

Physics
Using energy considerations and assuming negligible air resistance, find the speed of a rock just before it hits the water if it is thrown from a bridge 20.2 m above water with an initial speed of 13.4 m/s? (Verify that the speed is independent of the direction the rock is ...
Wednesday, March 16, 2016 by Anonymous

science physics
A penny is dropped from a window and takes 1.82s to reach the ground. From what height was it dropped.
Wednesday, March 16, 2016 by melisa

Physics
On a frozen pond, a 11.7 kg sled is given a kick that imparts to it an initial speed of v0 = 2.01 m/s. The coefficient of kinetic friction between sled and ice is μk = 0.111. Use the work kinetic energy theorem to find the distance the sled moves before coming to rest.
Wednesday, March 16, 2016 by Anonymous

Physics
A lift of mass 200kg moves upward with a uniform velocity of 4 m/s . if efficiency of motor is 70% then input power of motor is?
Wednesday, March 16, 2016 by rpzubaern

Physics - Repost because of no response
In an experiment on the shuttle, an electron with a speed of 6.3 x 105 m/s [N] and a mass of 9.11 x 10-31 kg is shot through an external magnetic field. Determine the strength and orientation of the magnetic field required so that the electron's direction of travel remains...
Wednesday, March 16, 2016 by Matt Damon

Science
1. Which of the following best describes the movement of an object at rest if no outside forces act on it? (1 point) It will move due to inertia. Gravity will eventually cause it to move. It will stay at rest due to inertia. It will stay at rest due to gravity. Physics 2. A 2,...
Wednesday, March 16, 2016 by Tanner fox

Physics
How do you determine the work done by the frictional force?
Wednesday, March 16, 2016 by Marie

physics
two trains pass each other on parallel track. the first is 180m and travel at 60k/m. the second is 120m and travel at 46k/h. calculate the total time taken to pass each other. (a) if travelling on the same direction (b) if travelling on opposite direction. thanks....... ...
Wednesday, March 16, 2016 by mr. peee

Physics Magnetic Field
In an experiment on the shuttle, an electron with a speed of 6.3 x 105 m/s [N] and a mass of 9.11 x 10-31 kg is shot through an external magnetic field. Determine the strength and orientation of the magnetic field required so that the electron's direction of travel remains...
Wednesday, March 16, 2016 by Matt Damon

Physics current directions
I need help In studying the cross section of a straight current carrying wire, you notice that the magnetic field lines run counter-clockwise. What is the direction of the current in the wire and how do you know? 2. You are looking into a current carrying solenoid and notice ...
Wednesday, March 16, 2016 by Matt Damon

Physics
The observed frequency of a train whistle is 513Hz as it approaches a stationary observer and is 432Hz as it recedes. Find the speed of the train
Wednesday, March 16, 2016 by maryam

Physics
The 2nd harmonic of a string of length 60cm and linear mass density 1.7g/m has the same frequency as the 5th possible harmonic of a closed pipe of length 1.2m. Find the tension in the string.
Wednesday, March 16, 2016 by maryam

physics
A police car moving at 75m/s is initially behind a truck moving in the same direction at 14m/s. The natural frequency of the car's siren is 1000Hz. What is the change in frequency observed by the truck driver as the car overtakes him?
Wednesday, March 16, 2016 by maryam

Physics current directions
I need help In studying the cross section of a straight current carrying wire, you notice that the magnetic field lines run counter-clockwise. What is the direction of the current in the wire and how do you know? 2. You are looking into a current carrying solenoid and notice ...
Wednesday, March 16, 2016 by Matt Damon

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Homework Help: Science