Monday

May 25, 2015

May 25, 2015

**physics**

A skier of mass 74.6 kg is pulled up a slope by a motor-driven cable. How much work is required to pull the skier 63.3 m up a 39.0◦ slope (assumed to be frictionless) at a constant speed of 2.0 m/s? The acceleration of gravity is 9.81 m/s 2 . Answer in units of J
*Thursday, January 29, 2015 at 8:59pm*

**physics**

Each vertical steel column of an office building supports a weight of 1.30 x 10^5 N and is compressed to 5.90 x 10^-3 A) Find the compression in each column if a wegith of 5.50 x 10^5 N is supported. B)If the compression of each steel column is 0.0710 cm, what wight is ...
*Thursday, January 29, 2015 at 8:41pm*

**Physics 201**

A person desires to reach a point that is 2.87 km from her present location and in a direction that is 47.5° north of east. However, she must travel along streets that are oriented either north-south or east-west. What is the minimum distance she could travel to reach her ...
*Thursday, January 29, 2015 at 7:53pm*

**URGENT PHYSICS**

Consider a case in which a 60 kg diver takes off from a diving board located at a height of 10 m above the water level and enters the water at a horizontal distance of 5 m from the end of the board. If the total time that the diver remains in the air is 2.5 seconds, determine ...
*Thursday, January 29, 2015 at 7:31pm*

**physics**

boy throws a penny into an empty well with an initial velocity of –2 m/s. He hears it hit the bottom 8 seconds later. About how far did the penny fall?
*Thursday, January 29, 2015 at 6:45pm*

**Physics**

A lobsterman’s buoy is a solid wooden cylinder of radius r and mass M. It is weighted at one end so that it floats upright in calm sea water, having density. A passing shark tugs on the slack rope mooring the buoy to a lobster trap, pulling the buoy down a distance x from...
*Thursday, January 29, 2015 at 6:43pm*

**physics**

An electron moving parallel to x axis has an initial speed of 2.51x106 m/s at the origin.Its speed is reduced to 1.76x105 m/s at the point x=3.12 cm. Calculate the potential difference, in Volts, between the origin and that point.
*Thursday, January 29, 2015 at 6:43pm*

**Physics**

This deals with Projectile Motion and I would be glad if someone were to check if my answers are correct. 1. c 2. b 3. a 4. d If air resistance were to be ignored, 1.a projectile that has a horizontal velocity is a)zero b)constant c)increasing d)decreasing 2.a projectile that ...
*Thursday, January 29, 2015 at 6:42pm*

**physics**

What potential difference is needed to stop an electron having an initial speed of 3.70x 105 m/s? Answer in volts
*Thursday, January 29, 2015 at 6:32pm*

**Physics**

Suppose you have a 3 C charge at (1,0) m and a -3 C charge at (-1,0) m. Find (a) the electric field at the point (0,3), and (b) the electric force on a charge of 3 nC placed at (0,3).
*Thursday, January 29, 2015 at 5:48pm*

**Physics**

A man in search of his dog drives first 13.3 mi northeast, then 17.3 mi straight south, and finally 6.85 mi in a direction 30.3° north of west. a) What is the magnitude of his resultant displacement? b) What is the direction of his resultant displacement? Express your ...
*Thursday, January 29, 2015 at 5:21pm*

**Physics**

A 50 cm diameter wheel rotates through 25 radians. How do I figure out the amount of distance it will move?
*Thursday, January 29, 2015 at 5:13pm*

**Need Help Physics**

The captain of a boat wants to travel directly across a river that flows due east with a speed of 1.09 m/s. He starts from the south bank of the river and wants to reach the north bank by travelling straight across the river. The boat has a speed of 6.44 m/s with respect to ...
*Thursday, January 29, 2015 at 5:12pm*

**Physics Help**

During a long airport layover, a physicist father and his 8-year-old daughter try a game that involves a moving walkway. They have measured the walkway to be 41.5 m long. The father has a stopwatch and times his daughter. First, the daughter walks with a constant speed in the ...
*Thursday, January 29, 2015 at 5:09pm*

**physics **

A ball of mass M1 moves with a velocity U1, collides perfectly elastically with a stationary ball of mass M2 . After the collision, M1 and M2 move with velocities V1 and V2 respectively. Show that : V1 =(M1-M2) / (M1 + M2 ) * U1 .
*Thursday, January 29, 2015 at 5:02pm*

**Physics**

By trial and error, a frog learns that it can leap a maximum horizontal distance of 1.26 m. If, in the course of an hour, the frog spends 27.5 % of the time resting and 72.5 % of the time performing identical jumps of that maximum length, in a straight line, what is the ...
*Thursday, January 29, 2015 at 5:01pm*

**physics**

CRITICAL THINKING: The term ”weight” in physics has the following very specific meaning: “The weight of an object is the name given to a particular force: the gravitational force exerted by the earth on the object, giving it an acceleration of 9.8 m/s2 near the ...
*Thursday, January 29, 2015 at 4:53pm*

**physics**

CRITICAL THINKING: The term ”weight” in physics has the following very specific meaning: “The weight of an object is the name given to a particular force: the gravitational force exerted by the earth on the object, giving it an acceleration of 9.8 m/s2 near the ...
*Thursday, January 29, 2015 at 4:53pm*

**physics**

Two forces of equal magnitude act on the same object. Which of the following must be true? a. The object is moving. b. The object is accelerating. c. If the object is initially at rest, it cannot remain at rest. d. The two forces form a third-law pair. e. None of the above.
*Thursday, January 29, 2015 at 4:52pm*

**physics**

Suppose a car is traveling at +25.0 m/s, and the driver sees a traffic light turn red. After 0.564 s has elapsed (the reaction time), the driver applies the brakes, and the car decelerates at 4.00 m/s2. What is the stopping distance of the car, as measured from the point where...
*Thursday, January 29, 2015 at 4:21pm*

**Physics**

Mark launches a projectile 65 degrees from the horizontal and it strikes the ground a certain distance away. For what other angle of launch at the same speed would the projectile land just as far away?
*Thursday, January 29, 2015 at 3:45pm*

**physics **

Consider a case in which a 60 kg diver takes off from a diving board located at a height of 10 m above the water level and enters the water at a horizontal distance of 5 m from the end of the board. If the total time that the diver remains in the air is 2.5 seconds, determine ...
*Thursday, January 29, 2015 at 3:01pm*

**Physics**

A spring of negligible mass stretches 3.00 cm from its relaxed length when a force of 7.10 N is applied. A 0.440-kg particle rests on a frictionless horizontal surface and is attached to the free end of the spring. The particle is displaced from the origin to x = 5.00 cm and ...
*Thursday, January 29, 2015 at 2:36pm*

**physics**

A baseball is hit and moves initially at an angle of 35.0 to the horizontal ground with a velocity of 25.0 m/s. (a) What are the vertical and horizontal components of the initial velocity? (b) How long will the ball be in the air? (c) What is the range?
*Thursday, January 29, 2015 at 2:27pm*

**physics**

You fire a cannon ball from ground level at a speed of 20.0 m/s ∠30.0 Find the time taken for the ball to hit the earth. How far will it land?
*Thursday, January 29, 2015 at 2:26pm*

**physics**

A ball rolls off a 1.40 m high table with an initial horizontal speed of 0.600 m/s. How far will it land?
*Thursday, January 29, 2015 at 2:23pm*

**physics**

Using the following number: 26,802 In 4 significant figures, this number would be Answer. In 3 significant figures, this number would be Answer. In 2 significant figures, this number would be Answer. In 1 significant figure, this number would b
*Thursday, January 29, 2015 at 1:55pm*

**physics**

A particular jet aircraft must reach a speed of 43 m/s in order to take-off. If the acceleration of the plane is 1329 m/s2, the minimum length of the runway is Answermeters
*Thursday, January 29, 2015 at 1:52pm*

**physics**

An aircraft has a lift off speed of 130 km/h. What minimum uniform acceleration does this require if the aircraft is to be airborne after a takeoff run of 350 m? Answer in units of m/s2
*Thursday, January 29, 2015 at 12:22pm*

**physics**

With an average acceleration of −1.3 m/s2 , how long will it take a cyclist to bring a bicycle with an initial speed of 13.7 m/s to a complete stop? Answer in units of s.
*Thursday, January 29, 2015 at 12:18pm*

**physics**

Heather and Matthew walk eastward with a speed of 0.90 m/s east. If it takes them 31 min to walk to the store, how far have they walked? Answer in units of km.
*Thursday, January 29, 2015 at 12:18pm*

**physics**

A speeder passes a parked police car at a constant speed of 20.1 m/s. At that instant, the police car starts from rest with a uniform acceleration of 2.65 m/s 2 . How much time passes before the speeder is overtaken by the police car? Answer in units of s.
*Thursday, January 29, 2015 at 12:16pm*

**physics**

A dragster is speeding down the track at 150m/s. its rear wheels are 2m in diameter, and its front wheels are 40cm in diameter. What are the angular velocities of the front and rear wheels, respectively?
*Thursday, January 29, 2015 at 11:34am*

**physics**

A block and tackle with a velocity of 5 is used to raise a mass of 25kg through a vertical distance of 40cm at a steady rate,if the effort is equal to 60N,determine the distance moved by effort, work done by the effort in lifting the load and the loss of energy involved in ...
*Thursday, January 29, 2015 at 11:06am*

**Physics**

an aircraft lands on a runway with length of 205 m at a speed of 295 km/h what is the minimum constant deceleration required for a safe landing
*Wednesday, January 28, 2015 at 11:58pm*

**physics**

A projectile is fired at 33.1° above the horizontal. Any effects due to air resistance are negligible. At the highest point in its trajectory, its speed is 15.5 m/s. Calculate the horizontal component of the initial velocity.
*Wednesday, January 28, 2015 at 11:48pm*

**Physics**

In the annual battle of the dorms, students gather on the roofs of Jackson and Walton dorms to launch water balloons at each other with slingshots. The horizontal distance between the buildings is 36.0 m, and the heights of the Jackson and Walton buildings are, respectively, ...
*Wednesday, January 28, 2015 at 11:31pm*

**PHYSICS**

a copper cylinder is initially at 20.0 degree Celsius. At what temperature will its volume be 0.150% larger than it is at 20.0 degree Celsius?
*Wednesday, January 28, 2015 at 10:28pm*

**physics**

What is the mass of 5.00L of pure water?
*Wednesday, January 28, 2015 at 10:24pm*

**physics**

What would be the charge on five alpha particles?(An alpha particle is helium nucleus) I started with 2 from the helium multiply by 5 and got 10. I don't know what to do next. Please help???
*Wednesday, January 28, 2015 at 9:55pm*

**Physics **

A spring with an unstrained length of 0.075 m and a spring constant of 2.7 N/m hangs vertically downward from the ceiling. A uniform electric field directed vertically upward fills the region containing the spring. A sphere with a mass of 4.84 10-3 kg and a net charge of +7.0...
*Wednesday, January 28, 2015 at 8:56pm*

**Physics**

A compact car, with mass 725kg, is moving at 115km/h toward the east.....find the magnitude and direction of it's momentum. Draw an arrow on your sketch showing the momentum
*Wednesday, January 28, 2015 at 7:11pm*

**physics**

A swimmer can swim 3 mph in still water. She decides to swim perpendicular to the river current which is 3 mph. If the river is 19.89 miles wide, it will take the swimmer ___ hours to cross the river.
*Wednesday, January 28, 2015 at 6:22pm*

**physics**

A swimmer can swim 1.7 mph in still water. She decides to swim upsteam against the current which is 0.7 mph. It will take the swimmer ___ hours to travel 8 miles as measured by a person standing on the river bank.
*Wednesday, January 28, 2015 at 6:19pm*

**physics**

A 4.3kg object moves across a floor with a velocity of + 8.2 m/s and slides to rest in 5.8 s. The net force producing this acceleration is:
*Wednesday, January 28, 2015 at 6:17pm*

**physics **

A typical multivitamin tablet can contain 2.00mg of vitamin B2 (riboflavin), and the RDA is 0.0030 g/day. How many such tablets should a person take each day to get the proper amount of this vitamin, assuming that he gets none from any other sources?
*Wednesday, January 28, 2015 at 5:13pm*

**Physics**

As mentioned, after the hovering period at 100 m , the vehicle made a vertical powered descent to h = 30 m, ending with a downward (!) velocity of 2 m/s at this altitude. Assume that the engine provided a constant (!) thrust-to-weight ratio during this phase and that the ...
*Wednesday, January 28, 2015 at 4:55pm*

**Physics **

Well, I just found out that I failed my physics midterm. I got a 51. Yes I studied but I still don't get the forces and inclined planes. And my parents are going to kill me if they find out. The midterm brought down my grade to a 79!! Any advice? P.S I also got a 71 on my ...
*Wednesday, January 28, 2015 at 3:27pm*

**Physics**

A 7.1 kg watermelon is placed at one end of a 5.9 m, 244 N scaﬀolding supported by two cables. One supporting cable is at the opposite end of the scaﬀolding, and the other is 0.54 m from the watermelon. How much tension is in the cable at the end of the sca&#...
*Wednesday, January 28, 2015 at 2:53pm*

**Physics**

An airplane cruises at 880km/h relative to the air. It is flying from Denver, Colorado due west to Reno, Neveda, a distance of 1200km and will then return. There is a steady 90km/h wind blowing to the east. What is the difference in flight time between the two legs of the trip?
*Wednesday, January 28, 2015 at 2:36pm*

**physics**

The three charges in the figure are at the vertices of an isosceles triangle. Calculate the work that needs to be expanded, in Joules, to bring the charges together (as shown.) Take q=5.7 μC. The length of base is b=2.30 m. The lengths of sides are s=5.80 m. The two ...
*Wednesday, January 28, 2015 at 2:09pm*

**physics**

Assuming that the human body has a 1.2-cm-thick layer of skin tissue and a surface area of 1.5m2 , estimate the rate at which heat is conducted from inside the body to the surface if the skin temperature is 34 ∘C. (Assume a normal body temperature of 37 ∘C for the ...
*Wednesday, January 28, 2015 at 12:53pm*

**physics**

The U.S. five-cent coin, the nickel, has a mass of 5.1 g, a volume of 0.719 cm3, and a total surface area of 8.54 cm2. Assuming that a nickel is an ideal radiator, how much radiant energy per second comes from the nickel, if it is at 24∘C?
*Wednesday, January 28, 2015 at 12:53pm*

**physics**

Assume a goose has a 2.2-cm-thick layer of feather down (on average) and a body surface area of 0.16m2 .What is the rate of heat loss (conduction only) if the goose, with a body temperature of 41 ∘C, is outside on a winter day when the air temperature is 12∘C?
*Wednesday, January 28, 2015 at 12:52pm*

**physics**

If 0.060kg of ice at 0 ∘C is added to 0.320kg of water at 25∘C in a 0.150-kg aluminum calorimeter cup, what is the final temperature of the water?
*Wednesday, January 28, 2015 at 12:51pm*

**physics**

a spring balance is tied to a massless inextenxible string a small object of mass 60kg is attached to the hook of the spring balance. this system is now whirled about a vertical axis so that object performs ucm with centripetal acceleration/21m/s^2.thespring balance will now ...
*Wednesday, January 28, 2015 at 7:46am*

**Physics**

An archer's bow applies a force to an arrow over a distance of 19cm, while firing it vertically upwards. If the arrow achieves a speed of 8.0m/s and the efficiency of the bow is 75%, determine the average force applied to the arrow by the bow. So far I have the Wnet for ...
*Wednesday, January 28, 2015 at 2:49am*

**physics**

A net force of (2.5 N)i hat − (4.7 N)j hat acts on a 3.2 kg object. Find the acceleration a with arrow.
*Wednesday, January 28, 2015 at 2:43am*

**physics**

A particle is traveling in a straight line at a constant speed of 29.9 m/s. Suddenly, a constant force of 14.5 N acts on it, bringing it to a stop in a distance of 58.2 m. (a) What is the direction of the force? (b) Determine the time it takes for the particle to come to a ...
*Wednesday, January 28, 2015 at 2:41am*

**maths**

A survey o 85 students asked them about the subjects they liked to study 35 students liked maths,37liked history,26 liked physics,20 liked maths and history,14 liked maths and physics,2 liked all the subjects. a) how many of these students like maths and physics? B) how many ...
*Wednesday, January 28, 2015 at 1:35am*

**Physics**

What mass of water requires 1.89X10^8 joules of energy to heat from 15 degrees Celsius to 75 degree celsius? The specific heat of water is 4190 J/kg degree celsius
*Wednesday, January 28, 2015 at 1:28am*

**Physics**

How much heat is contained in 100 kg of water at 60.0 °C?
*Tuesday, January 27, 2015 at 11:14pm*

**Physics**

A soccer ball is kicked with a velocity of 12m/s, HORIZONTALLY off a building which is 8.5m high. What is the velocity of the ball after 1.25s? This is what I found so far: Vi = 12m/s Dx = 15.8049336m Dy = 8.5m Time it took for ball to hit floor 1.31707778s I used D=Vi(T) + 1/...
*Tuesday, January 27, 2015 at 10:21pm*

**physics**

6) CRITICAL THINKING: Kinematic equations are only valid for situations with constant acceleration. Using Newton’s second law, explain some examples of non-constant acceleration?
*Tuesday, January 27, 2015 at 9:43pm*

**physics**

The net force vector for an object in motion is a. always in the same direction as the object's acceleration vector. b. sometimes in the same direction as the object's acceleration vector. c. always in the same direction as the object's velocity vector. d. always ...
*Tuesday, January 27, 2015 at 9:43pm*

**physics**

A 200-kg rock is being pulled upward with an acceleration of 3 m/s2. The net force on the rock is
*Tuesday, January 27, 2015 at 9:42pm*

**Physics**

3. An 80 kg skier is skiing down a slope (assume its frictionless) as shown in the diagram. The skier then hits a patch of sandy snow that applies a constant frictional force of 320 N directed up the slope. a. What is the skiers acceleration before hitting the sandy snow? b. ...
*Tuesday, January 27, 2015 at 9:39pm*

**Physics**

A +1.3-nC point charge is placed at one corner of a square (1.1 m on a side), and a -3.1-nC charge is placed on the corner diagonally opposite. What is the magnitude of the electric field at either of the other two corners?
*Tuesday, January 27, 2015 at 9:30pm*

**physics**

Two 4.0cm × 4.0cm square aluminum electrodes, spaced 0.50mm apart are connected to a 300V battery. What is the charge on the positive electrode? I already found the capacitance which turned out to be 28 pF.
*Tuesday, January 27, 2015 at 8:55pm*

**Physics**

A bicycle wheel has a diameter of 47.6 cm and a mass of 0.809 kg. The bicycle is placed on a stationary stand on rollers and a resistive force of 60.1 N is applied to the rim of the tire. Assume all the mass of the wheel is concentrated on the outside radius. In order to give ...
*Tuesday, January 27, 2015 at 8:27pm*

**Physics**

A bicycle wheel has a diameter of 47.6 cm and a mass of 0.809 kg. The bicycle is placed on a stationary stand on rollers and a resistive force of 60.1 N is applied to the rim of the tire. Assume all the mass of the wheel is concentrated on the outside radius. In order to give ...
*Tuesday, January 27, 2015 at 8:22pm*

**Physics**

A soccer ball is kicked with a velocity of 12m/s, HORIZONTALLY off a building which is 8.5m high. What is the velocity of the ball after 1.25s? This is what I found so far: Vi = 12m/s Dx = 15.8049336m Dy = 8.5m Time it took for ball to hit floor 1.31707778s I used D=Vi(T) + 1/...
*Tuesday, January 27, 2015 at 8:21pm*

**physics**

A block with initial velocity of 3 m/s slides 9m across a rough horizontal surface before coming to rest. What is the coefficient of kinetic friction? V^2=Vo^2+2ax 0=9+18x a=-1/2 Ffr=mukFn Sigma F=ma ma=mukFn
*Tuesday, January 27, 2015 at 8:11pm*

**Physics**

A(n) 0.491 kg football is thrown with a speed of 17.8 m/s. A stationary receiver catches the ball and brings it to rest in 0.0147 s. What is the magnitude of the impulse de- livered to the ball? Answer in units of kg · m/s
*Tuesday, January 27, 2015 at 7:58pm*

**Physics**

A 0.145 kg baseball pitched at 39.9 m/s is hit on a horizontal line drive straight back toward the pitcher at 52.0 m/s. If the contact time between r the bat and ball is .001 s, calculate the average force between the ball and bat during contact. I know the answer is 13300 N, ...
*Tuesday, January 27, 2015 at 7:14pm*

**physics**

A boy on a 2.2 kg skateboard initially at rest tosses a(n) 8.4 kg jug of water in the forward direction. If the jug has a speed of 3.0 m/s relative to the ground and the boy and skateboard move in the opposite direction at 0.60 m/s, find the boy’s mass. Answer in units of kg
*Tuesday, January 27, 2015 at 7:13pm*

**Physics**

By trial and error, a frog learns that it can leap a maximum horizontal distance of 1.26 m. If, in the course of an hour, the frog spends 27.5 % of the time resting and 72.5 % of the time performing identical jumps of that maximum length, in a straight line, what is the ...
*Tuesday, January 27, 2015 at 5:11pm*

**Physics**

An object fired at an angle of 31.9° above the horizontal takes 2.55 s to travel the last 15.5 m of its vertical distance and the last 10.5 m of its horizontal distance. With what speed was the object launched? (Note: This problem does not stipulate that the initial and ...
*Tuesday, January 27, 2015 at 5:10pm*

**Physics**

A plane diving with constant speed at an angle of 52.5° with the vertical, releases a package at an altitude of 499 m. The package hits the ground 3.87 s after release. How far horizontally does the package travel?
*Tuesday, January 27, 2015 at 5:10pm*

**Physics **

What is the maximum height above ground a projectile of mass 0.67 kg, launched from ground level, can achieve if you are able to give it an initial speed of 78.5 m/s?
*Tuesday, January 27, 2015 at 5:10pm*

**Physics**

For a science fair competition, a group of High School students built a kicker-machine that can launch a golf ball from the origin with a velocity of 12.9 m/s and initial angle of 31.7° with respect to the horizontal. a) Where will the golf ball fall back to the ground? ...
*Tuesday, January 27, 2015 at 5:09pm*

**Physics**

You are practicing throwing darts in your dorm. You stand 3.21 m from the wall on which the board hangs. The dart leaves your hand with a horizontal velocity at a point 1.94 m above the ground. The dart strikes the board at a point 1.73 m from the ground. a) Calculate the time...
*Tuesday, January 27, 2015 at 5:09pm*

**Physics**

In an action movie, the heroine is supposed to jump with a motorcycle from the roof of one skyscraper to another one. The roof of the second skyscraper is h=9 meters lower, and the gap between the buildings is d=15 meters wide. Both roofs are horizontal and flat. Neglecting ...
*Tuesday, January 27, 2015 at 5:08pm*

**Physics**

A juggler tosses a ball h = 2 m into the air with one hand and catches it with the other hand at the same level. Neglecting air resistance, how long is the ball in the air?
*Tuesday, January 27, 2015 at 5:08pm*

**Physics**

If you throw a ball into the air at some angle with respect to the horizontal, which of the following statements about the ball is true? The acceleration is zero at the top of the motion The horizontal component of the velocity is zero at the top of the motion The velocity is ...
*Tuesday, January 27, 2015 at 5:08pm*

**Physics**

Pease evaluate the statements by choosing from these three statements Always true: the statement is true under any circumstances Not necessarily true: the statement may be true in some circumstances, but not in others Always false: under no circumstances is this true 1. If you...
*Tuesday, January 27, 2015 at 5:07pm*

**Physics**

The captain of a boat wants to travel directly across a river that flows due east with a speed of 1.09 m/s. He starts from the south bank of the river and wants to reach the north bank by travelling straight across the river. The boat has a speed of 6.44 m/s with respect to ...
*Tuesday, January 27, 2015 at 5:06pm*

**Physics**

The air speed indicator of a plane that took off from Detroit reads 349 km/h and the compass indicates that it is heading due east to Boston. A steady wind is blowing due north at 46.5 km/h. a) Calculate the speed of the plane with reference to the ground. b) If the pilot ...
*Tuesday, January 27, 2015 at 5:05pm*

**Physics**

A swimmer is heading straight for the other shore of a river with a velocity of vs=0.5 m/s relative to the water, but is carried away by the current, which has a velocity of vr=0.4 m/s. It takes her 20.6 s to get across. How far downstream does she end up?
*Tuesday, January 27, 2015 at 5:05pm*

**Physics**

During a long airport layover, a physicist father and his 8-year-old daughter try a game that involves a moving walkway. They have measured the walkway to be 41.5 m long. The father has a stopwatch and times his daughter. First, the daughter walks with a constant speed in the ...
*Tuesday, January 27, 2015 at 5:05pm*

**Physics **

A man in search of his dog drives first 13.3 mi northeast, then 17.3 mi straight south, and finally 6.85 mi in a direction 30.3° north of west. 1. a) What is the magnitude of his resultant displacement? 2. b) What is the direction of his resultant displacement? Express ...
*Tuesday, January 27, 2015 at 5:04pm*

**physics**

Two towers(the towers are the same) are built next to each other. the distance between them is d and there height is 10,000d. a ball is thrown horizontally from one tower to the other with spped v=sqrt(gd/2). assuming the ball collied elasticlly with the wall, therfore his ...
*Tuesday, January 27, 2015 at 3:56pm*

**physics- vectors **

In the sum Vector A plus Vector B equals vector C, vector A has a magnitude of 11.6 m and is angled 36.5° counterclockwise from the +x direction, and vector C has a magnitude of 14.0 m and is angled 17.1° counterclockwise from the -x direction. What are (a) the ...
*Tuesday, January 27, 2015 at 3:27pm*

**Physics**

A 26.3 g marble sliding to the right at 21.0 cm/s overtakes and collides elastically with a 13.3 g marble moving in the same direction at 12.2 cm/s. After the collision, the 13.3 g marble moves to the right at 23.7 cm/s. Find the velocity of the 26.3 g marble after the collision.
*Tuesday, January 27, 2015 at 3:02pm*

**Physics**

What is the gravitational force between two 10 kg iron balls separated by a distance of 0.1 m? How does this compare with the weight of one ball?
*Tuesday, January 27, 2015 at 2:31pm*

**Physics**

What is the Earth's gravitational force on you when you are standing on the Earth and when you are riding in the Space Shuttle 380 km above the Earth's surface? Answer as a fraction of the surface gravity of Earth. (The Earth's radius is 6400 km.)
*Tuesday, January 27, 2015 at 1:55pm*

**physics**

A rod with length L and mass m stand on a frictionless table. a ball with mass m and speed u cimped perpendicular to the rod a distance x from the bottom of the rod and sticks to it. what is the angular velocity of the rod+ball after the collison? I need help on how to solve ...
*Tuesday, January 27, 2015 at 12:49pm*

**Physics **

In the sum Vector A plus Vector B equals vector C, vector A has a magnitude of 11.6 m and is angled 36.5° counterclockwise from the +x direction, and vector C has a magnitude of 14.0 m and is angled 17.1° counterclockwise from the -x direction. What are (a) the ...
*Tuesday, January 27, 2015 at 12:44pm*

**Physics**

A 10.0-kg block is released from point A in Figure P8.57. The track is frictionless except for the portion between points B and C , which has a length of 6.00 m. The block travels down the track, hits a spring of force constant 2 250 N/m, and compresses the spring 0.300 m from...
*Tuesday, January 27, 2015 at 5:56am*

**Physics **

A small rocket is fired in a test range. It rises high into the air and soon runs out of fuel. On the way down it passes near an observer (sitting in a 21.5-m-high tower) who sees the rocket traveling at a speed of 35 m/s and moving in a vertical plane at an angle of 56° ...
*Tuesday, January 27, 2015 at 3:36am*