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February 28, 2015

February 28, 2015

**Recent Homework Questions About Physics**

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**Physics**

A 30-caliber rifle with a mass of 3.54 kg fires a 7.33- g bullet with a speed of 596 m/s with respect to the ground. What kinetic energy is released by the explosion of the gunpowder that fires the bullet? (Note there is a tolerance 0.1 percent for the answer)
*Friday, November 21, 2014 at 1:19pm*

**physics**

A dog sled team is pulling a sled across a flat patch of snow. The total force exerted by the four dogs is 475 N (applied horizontally). The sled (with driver on it) weighs 350 kg. and the coefficient of kinetic friction between the sled and the ground is (a) What is the ...
*Friday, November 21, 2014 at 11:44am*

**Physics**

A distant planet has a mass of 0.6400 ME and a radius of 0.9000 RE. What is the ratio of the escape speed from this planet to the escape speed from the earth?
*Friday, November 21, 2014 at 11:20am*

**Physics**

2 vectors have same magnitude.The magnitude of the resultant vector of these 2 vectors are same as either of both vectors.What is the angle between 2 vectors?
*Friday, November 21, 2014 at 7:18am*

**physics**

If the athlete lies down on the ground on his back,his weight is spread over an area of 0.75 meter square. How much pressure does he exert on the ground in this position?
*Friday, November 21, 2014 at 6:06am*

**physics**

A particle of mass and initial velocity strikes a stationary particle of mass . The collision is elastic. It is observed that after the collision the particles have equal and opposite velocities: Find (a) the ratio ; (b) the velocity of the CM (before and after the collision...
*Friday, November 21, 2014 at 5:57am*

**physics**

A car of mass 200g moving at 15.0m/s is accelerated to 25.0m/s in a time of 10.0 seconds determine the accelerating force and calculate the work done on the body
*Friday, November 21, 2014 at 4:18am*

**physics**

A 5 ft chain is sitting on a table with 2 ft hanging off (3 ft sitting on table). The table is 4 ft high, and the chain slides frictionless off the table. The chain weighs 15 lb. What is the velocity of the chain when it first hits the ground.
*Friday, November 21, 2014 at 12:51am*

**physics**

a race car starts from rest on a circular track.the car increases its speed at constant rate at as it goes 2.75 times around the track.find the angle that the total acceleration of the car makes with the radius connecting the centre of the track and the car at the moment the ...
*Friday, November 21, 2014 at 12:05am*

**Physics**

Two workers are sliding 310kg crate across the floor. One worker pushes forward on the crate with a force of 440N while the other pulls in the same direction with a force of 230N using a rope connected to the crate. Both forces are horizontal, and the crate slides with a ...
*Friday, November 21, 2014 at 12:03am*

**Physics**

A chair of weight 85.0N lies atop a horizontal floor; the floor is not frictionless. You push on the chair with a force of F = 45.0N directed at an angle of 34.0∘ below the horizontal and the chair slides along the floor. Using Newton's laws, calculate n, the ...
*Thursday, November 20, 2014 at 11:35pm*

**physics**

A motorcross racer covers one lap of a 1200 meter track on his motorcycle at a speed of 27 meters per second. How long does it take to ride one lap: A. In seconds? B. In minutes?
*Thursday, November 20, 2014 at 11:34pm*

**Physics**

A swimmer can swim at 3.9m/s in still water. What will the swimmer's speed be (relative to the shore) if he crosses a river that is flowing at 5.1m/s?
*Thursday, November 20, 2014 at 10:59pm*

**physics**

note ... find acceleration by using distance and time (ignore ”incline” ... just treat it like linear motion of object starting from rest). A 1.8 kg mass starts from rest and slides down an inclined plane 8.8×10−1 m long in 0.54 s. What net force is ...
*Thursday, November 20, 2014 at 10:16pm*

**Physics **

A particle moving at a velocity of 8 m/s in the positive x direction is given an acceleration of 7.4 m/s2 in the positive y direction for 1.7 s. What is the final speed of the particle? Answer in units of m/s
*Thursday, November 20, 2014 at 10:07pm*

**Physics**

A plane designed for vertical takeoff has a mass of 6.4 ✕ 103 kg. Find the net work done by all forces on the plane as it accelerates upward at 8.4 m/s2 through a distance of 30.0 m after starting from rest.
*Thursday, November 20, 2014 at 8:48pm*

**Physics**

A skier of mass 67.0 kg is pulled up a slope by a motor-driven cable. How much work is required to pull the skier 59 m up a 32° slope (assumed to be frictionless) at a constant speed of 2.0 m/s?
*Thursday, November 20, 2014 at 8:47pm*

**physics**

A 67.0 kg ice skater moving to the right with a velocity of 2.02 m/s throws a 0.12 kg snowball to the right with a velocity of 21.5 m/s relative to the ground. (a) What is the velocity of the ice skater after throwing the snowball? Disregard the friction between the skates and...
*Thursday, November 20, 2014 at 8:46pm*

**physics 1**

A spy in a speed boat is being chased down a river by government officials in a faster craft. Just as the officials' boat pulls up next to the spy's boat, both boats reach the edge of a 4.5m waterfall. The spy's speed is 16m/s and the official's speed is 24m/s...
*Thursday, November 20, 2014 at 8:32pm*

**physics**

Suppose that a sprinter can reach maximum speed by accelerating uniformly for 1.7 seconds. What maximum speed must this sprinter maintain in order to equal the world's record of 19.5 seconds for 200 meters?
*Thursday, November 20, 2014 at 8:22pm*

**physics**

if a bird travels 150 cm for 10 sec then 100 cm for 10 sec and then 200 cm for 5 sec. What was the birds average speed?
*Thursday, November 20, 2014 at 8:04pm*

**physics**

A 278 g particle is released from rest at point A inside an smooth hemispherical bowl of radius 36.5 cm, as shown below. (a) Calculate the gravitational potential energy at A relative to B. J (b) Calculate the particle's kinetic energy at B. J (c) Calculate the particle&#...
*Thursday, November 20, 2014 at 7:53pm*

**physics**

Tarzan swings on a 23.2 m long vine initially inclined at an angle of 22° from the vertical. (a) What is his speed at the bottom of the swing if he starts from rest? m/s (b) What is his speed at the bottom of the swing if he starts with an initial speed of 2.58 m/s? m/s
*Thursday, November 20, 2014 at 7:39pm*

**physics**

A student fires a rocket at 24 degrees above the horizontal. The 10kg rocket comes out of the gun barrel at 1000 m/s, and accelerates 15 m/s^2 uniformly until it burns out 2 seconds later. It then is acted apon by gravity until it hits the ground. I need to see a drawn out ...
*Thursday, November 20, 2014 at 7:33pm*

**Chemistry/Physics**

When 1mol of a gas burns at constant pressure, it produces 2430J of heat and does 5kJ of work. Calculate change in H, q, and in kJ?
*Thursday, November 20, 2014 at 7:30pm*

**Chemistry/Physics**

The kinetic energy of a rolling billiard ball is given by KE=1/2mv2. Suppose a 0.17-kg billiard ball is rolling down a pool table with an initial speed of 4.7m/s . As it travels, it loses some of its energy as heat. The ball slows down to 3.8m/s and then collides straight-on ...
*Thursday, November 20, 2014 at 7:27pm*

**ap physics**

A spy in a speed boat is being chased down a river by government officials in a faster craft. Just as the officials' boat pulls up next to the spy's boat, both boats reach the edge of a 4.5m waterfall. The spy's speed is 16m/s and the official's speed is 24m/s...
*Thursday, November 20, 2014 at 7:26pm*

**physics **

A 78 g basketball is launched at an angle of 45.4◦ and a distance of 10.1 m from the basketball goal. The ball is released at the same height (ten feet) as the basketball goal’s height. A basketball player tries to make a long jump-shot as described above. The ...
*Thursday, November 20, 2014 at 6:39pm*

**Physics-**

How can anything accelerate if every force has and equal and opposite counterpart?
*Thursday, November 20, 2014 at 6:20pm*

**physics**

A car (mass = 860 kg) is at rest on the top of a tall hill. the car rolls down the hill and at the bottom, reaches a top speed of 19 m/s. A) find the force of gravity on the car 560 x 9.8 = 5488 N B) find the work done by gravity on the car W = change in energy = kinetic ...
*Thursday, November 20, 2014 at 5:47pm*

**physics**

the motion of a body is described in simple harmonic motion as x=Cos(wt).when the body is 0.2m from the mid of its path , velocity is 3m/s and when it is 0.8m from the center of its path, its velocity is 1m/s ,determine: 1.the period 2.greatest acceleration
*Thursday, November 20, 2014 at 4:56pm*

**physics**

A box has mass 13 kg and is at rest on a flat floor. A minimum force of 47 N is needed to push the box so it moves across the floor. What is the coefficient of static friction between the box and floor?
*Thursday, November 20, 2014 at 4:24pm*

**physics**

A white billiard ball with mass mw = 0.1 kg is moving with a speed of v = 0.5 m/s making angle 60 degree and collides with a black billiard ball with the same mass mb = 0.1 kg that is initially at rest. The distance between the black ball and the pocket is 10cm\ friction exist...
*Thursday, November 20, 2014 at 2:59pm*

**physics**

A 4.53 kg particle has a velocity of vx = 3.98 m/s and vy = −3.16 m/s. Find the magnitude of its total momentum. Answer in units of kg · m/s
*Thursday, November 20, 2014 at 2:48pm*

**physics**

1) How many seconds does it take a car traveling 40 mph, decelerating at a rate of 7 miles per second, to come to a complete stop? 2) How many feet?
*Thursday, November 20, 2014 at 2:00pm*

**Physics**

A 30-caliber rifle with a mass of 3.54 kg fires a 7.33- g bullet with a speed of 596 m/s with respect to the ground. What kinetic energy is released by the explosion of the gunpowder that fires the bullet? (Note there is a tolerance 0.1 percent for the answer)
*Thursday, November 20, 2014 at 11:08am*

**Physics**

A distant planet has a mass of 0.6400 ME and a radius of 0.9000 RE. What is the ratio of the escape speed from this planet to the escape speed from the earth?
*Thursday, November 20, 2014 at 10:14am*

**Physics **

A sample contains 3.5×1019 radioactive atoms with a half life of 10000 years. How many atoms are expected to decay in the first second? After waiting 10000 years, how many atoms are expected to decay in the next second?
*Thursday, November 20, 2014 at 9:54am*

**physics**

A carnival clown, 80 kg, rides a motorcycle down a ramp and then up and around a large, vertical loop. If the loop has a radius of 18 m, what is the force that the track exerts on the rider at the TOP of the loop if the clown is traveling at an impressive speed of 15 m/s?
*Thursday, November 20, 2014 at 9:51am*

**physics**

A 75 kg pilot flies a plane in a vertical loop. At the top of the loop, when the plane is completely upside-down for an instant, the pilot hangs freely in the seat and does not push against the seat belt or seat. The airspeed indicator reads 120 m/s. What is the radius of the ...
*Thursday, November 20, 2014 at 9:48am*

**Physics**

new package moving system in the new improved post office consists of a large circular disc which rotates once every 5 seconds at a constant speed in a horizontal plane. packages are put on outer edge of turntable on one side of room and removed on opposite side. coefficient ...
*Thursday, November 20, 2014 at 8:54am*

**physics**

a certain tower is 40 m tall. a man drops a lanzones from the top of onto the head of his enemy. if the enemy is walking at a speed of 1.2 m/s, ho many meters should the enemy be from the position below the lanzones when it is dropped ?
*Thursday, November 20, 2014 at 8:42am*

**Physics**

object of mass 2 kg is attached to string and rotate in vertical circle of radius 1 m. at highest point it has velocity of 4 m/s. what is tension in string at that point. at lowest point it is .5 m above ground. if string breaks at highest point how far does it travel ...
*Thursday, November 20, 2014 at 8:38am*

**physics**

The coefficient of kinetic friction between tires and dry pavement is about 0.80. Assume that while travelling at 27m/s you lock your brakes and as a result the only horizontal force on the car is the frictional one. How many seconds does it take you to bring your car to a stop?
*Thursday, November 20, 2014 at 5:11am*

**Physics**

You are unloading a refrigerator from a delivery van. The ramp on the van is 5.0m long and its top end is 1.4m above the ground. As the refrigerator moves down the ramp, you are on the downside of the ramp trying to slow the motion by pushing horizontally against the ...
*Thursday, November 20, 2014 at 5:06am*

**Physics**

Disk 1(of mass m) slides with speed 1.0 m/s across a low friction surface and collides with disk 2( of mass 2m) originally at rest. Disk 1 is observed to bounce off at an angle of 15degrees to its original line of motion, while disk 2 moves at an angle of 55degrees. a) What is...
*Thursday, November 20, 2014 at 4:59am*

**physics**

how long the ball takes to reach the groud
*Thursday, November 20, 2014 at 4:04am*

**physics**

If 25cm3 of a quantity of wood ash has a mass of 45g,calculate the density of wood ash in kgm-3
*Thursday, November 20, 2014 at 3:30am*

**physics**

a cylindrical wire of lenght 2.80m and a radius of 1.35A, when the voltage of 0.0320v is applied across the ends of the wire. from what material is the wire made of?
*Thursday, November 20, 2014 at 1:16am*

**physics **

A kettle brings water to boil by using 233 C of charge over the course of 1.25 minutes. The amount of current that was used is _.__ A?
*Wednesday, November 19, 2014 at 11:58pm*

**Physics help please**

A 0.504 m length of conducting wire carrying a current of 62.1 A is?
*Wednesday, November 19, 2014 at 11:54pm*

**physics **

A lightning strike transfers 25.1 C of charge in (6.49x10^-3) s. The current during this lightning strike is _.__x10^ A?
*Wednesday, November 19, 2014 at 11:53pm*

**Physics**

1. Determine the specific heat of a certain metal if a 450-g sample of it loses 34,500 joules of heat as its temperature drops by 97degC. 2. The temperature of a 55-g sample of a certain metal drops by 113degC as it losses 3,500 J of heat. What is the specific heat of the ...
*Wednesday, November 19, 2014 at 10:14pm*

**Physics**

A woman on a bicycle traveling at 10m/s on a horizontal road stops pedaling as she starts up a hill inclined at an angle of 10° to the horizontal. How far up the hill does she travel before coming to rest? I really don't understand this question. Please help!
*Wednesday, November 19, 2014 at 8:37pm*

**physics**

what should the ratio of mass to volume be when considering the flight of a hot air balloon.
*Wednesday, November 19, 2014 at 7:24pm*

**physics**

a swimmer dives off a pier at an angle of 25 degrees from the horizontal with an initial velocity of 3.2 m/s. How far from the pier will the diver hit the water. Assume the level of water is the same as the pier.
*Wednesday, November 19, 2014 at 7:05pm*

**physics**

An astronaut (mass of 100 kg, with equipment) is headed back to her space station at a speed of 0.750 m/s but at the wrong angle. To correct her direction, she fires rockets from her backpack at right angles to her motion for a brief time. These directional rockets exert a ...
*Wednesday, November 19, 2014 at 6:47pm*

**physics**

A spider moving downward with a terminal velocity of 13m/s has an upward force of 22N acting on it...what is the mass of the spider?
*Wednesday, November 19, 2014 at 6:12pm*

**physics**

You are trying to find out how high you have to pitch a water balloon in order for it to burst when it hits the ground. You discover that the balloon bursts when you have pitched it to a height of 17 m. With what velocity did the balloon hit the ground? The acceleration of ...
*Wednesday, November 19, 2014 at 5:40pm*

**physics**

If a person pushes on a block and it travels a distance of 6.0m before stopping. How far would the block travel if it were pushed with the same force, but on the moon(which has 1/6 of the earth's gravity).
*Wednesday, November 19, 2014 at 5:35pm*

**Physics **

A meteorite weighing 1860N strikes the earth with a velocity of 45.2m/s. What is its kinetic energy? Write in SN to one decimal place. When I plugged in (1/2)(1860N)(45.2m/s)^2, I got the answer 1.9e6, but it was incorrect. Please help. I'm really confused!
*Wednesday, November 19, 2014 at 5:27pm*

**Physics **

Calculate the power needed from the motor of an elevator for it to be able to lift a 1x10^4kg mass a distance of 20m in 5s. (Enter your answer in scientific notation utilizing "e" format and rounding the decimal value to one decimal place.) I used the equation p = w/...
*Wednesday, November 19, 2014 at 5:21pm*

**physics**

The barrel of a rifle has a length of 0.976 m. A bullet leaves the muzzle of a rifle with a speed of 561 m/s. What is the acceleration of the bullet while in the barrel? A bullet in a rifle barrel does not have constant acceleration, but constant acceleration is to be assumed ...
*Wednesday, November 19, 2014 at 5:17pm*

**physics**

Two airplanes leave an airport at the same time. The velocity of the first airplane is 710 m/h at a heading of 27.5 ◦ . The velocity of the second is 650 m/h at a heading of 167◦ . How far apart are they after 3.3 h? Answer in units of m
*Wednesday, November 19, 2014 at 5:07pm*

**physics**

The initial speed of a body is 6.64 m/s. What is its speed after 1.38 s if it accelerates uniformly at 4.7 m/s 2 ? Answer in units of m/s
*Wednesday, November 19, 2014 at 5:02pm*

**physics**

A uniform electric field exists everywhere in the x, y plane. This electric field has a magnitude of 5700 N/C and is directed in the positive x direction. A point charge -5.4 × 10-9 C is placed at the origin. Find the magnitude of the net electric field at (a) x = -0.13...
*Wednesday, November 19, 2014 at 4:08pm*

**physics**

Two point charges are fixed on the y axis: a negative point charge q1 = -26 μC at y1 = +0.17 m and a positive point charge q2 at y2 = +0.35 m. A third point charge q = +9.5 μC is fixed at the origin. The net electrostatic force exerted on the charge q by the other ...
*Wednesday, November 19, 2014 at 3:39pm*

**physics**

Two tiny conducting spheres are identical and carry charges of -18.1C and +47.4C. They are separated by a distance of 3.55 cm. (a) What is the magnitude of the force that each sphere experiences? (b) The spheres are brought into contact and then separated to a distance of 3.55...
*Wednesday, November 19, 2014 at 3:31pm*

**physics **

A roller coaster car of mass 400kg starts from rest at point A and passes the point B with a speed of 3m/s.if the distance from A to B along the tracks is 20m,how large is the average friction force retarding the motion of the car
*Wednesday, November 19, 2014 at 12:30pm*

**physics**

A person is stranded and sitting 45m above the ground on the ledge of the cliff. of a safety rope is launched upward at an angle of 50 degrees above the horizontal at a distance of 60m away, what is the initial velocity of the rope so that it reaches the stranded person?
*Wednesday, November 19, 2014 at 12:22pm*

**Physics**

A naked person (e=0.75) with a surface area 2.00 square meters and a skin temperature of 34 degrees Celsius is in sauna at 90 degrees Celsius. If he stays in the sauna for 30 minutes, (a) How much heat does the perspn radiates? (b) How much heat does he absorb from the walls ...
*Wednesday, November 19, 2014 at 11:26am*

**physics**

Determine the quantity of heat required to convert 1kg of ice at −20 degrees Celsius to water at 100 degrees Celsius? Specific heat capacities of water and ice water are 2302 J/kgK and 4186 J/kgK respectively
*Wednesday, November 19, 2014 at 4:41am*

**Physics**

Janet jumps off a high diving platform with a horizontal velocity of 2.71 m/s and lands in water 1.6s later. How high is the platform? Acceleration of gravity is 9.8m/s^2. Answer in units of m.
*Tuesday, November 18, 2014 at 11:21pm*

**Physics**

Bill kicks a rock off the top of his apartment building. It strikes a window across the street 15m away. The acceleration of gravity is 9.8 m/s^2. If the window is 13m below the position where Bill contacted the rock, how long was it in the air?
*Tuesday, November 18, 2014 at 10:56pm*

**physics**

A plane drops a hamper of medical supplies from a height of 2560 m during a practice run over the ocean. The plane’s horizontal velocity was 116 m/s at the instant the hamper was dropped.What is the magnitude of the overall velocity of the hamper at the instant it strikes...
*Tuesday, November 18, 2014 at 10:47pm*

**physics**

A bee flies to a flower 583 m due south of its hive. The bee’s speed in still air is 0.68 m/s, and there is a wind blowing toward the south at 0.16 m/s. How long will it take the bee to travel to the flower and back to the hive? Answer in units of s
*Tuesday, November 18, 2014 at 10:44pm*

**physics**

a police shot a wall of 10 meter which is located 75 meter from himself. the angle between base and bullet was 60 degree and the speed was 30 meter per second was shot. was the bullet shot the wall ornot ..Explain if why?
*Tuesday, November 18, 2014 at 10:23pm*

**physics**

An airplane is flying at constant speed of 500 km/h on a straight line at 33000 feet above sea level. What is the net force acting on the plane?
*Tuesday, November 18, 2014 at 9:03pm*

**physics**

An airplane is flying at constant speed of 500 km/h on a straight line at 33000 feet above sea level. What is the net force acting on the plane?
*Tuesday, November 18, 2014 at 9:03pm*

**Physics**

A car of mass 1060 kg is on an icy driveway inclined at an angle of 39◦ . The acceleration of gravity is 9.8 m/s 2 . θ If the incline is frictionless, what is the acceleration of the car? Answer in units of m/s 2
*Tuesday, November 18, 2014 at 7:58pm*

**physics**

A 2.31 × 103 kg car requires 4.2 kJ of work to move from rest to some ﬁnal speed. During this time, the car moves 26.0 m. Neglecting friction, ﬁnd a) the ﬁnal speed. Answer in units of m/s
*Tuesday, November 18, 2014 at 7:27pm*

**Physics C**

A rifle is aimed horizontally at a target 100 ft away. The bullet hits the target .78in below the aiming point. a) What is the bullet's time of flight? b)What is its muzzle velocity? The answers should be a) 63 m/s b) 1.6 X 10 exponent 3 ft/s I don't know how to get to...
*Tuesday, November 18, 2014 at 7:11pm*

**Physics**

A 5.00 x 102 kg hot air balloon takes off from rest at the surface of the earth. The buoyant force lifts the balloon straight up, performing 9.70 x 104 J of work on the balloon. At the instant the balloon's upward speed is 4.08 m/s, the balloon will be ____ m above the ...
*Tuesday, November 18, 2014 at 6:12pm*

**physics**

Calculate the velocity of a skateboarder who accelerates from rest for 6.7 seconds down a ramp at an acceleration of 6.5 m/s2
*Tuesday, November 18, 2014 at 6:06pm*

**physics**

with a cart of unknown mass, could you still determine whether its total energy is conserved? explain your reasoning
*Tuesday, November 18, 2014 at 5:10pm*

**physics 9th grade **

What is the impulse that must be applied to stop a 90-kilogram running back on a field at a speed of 4.5 meters per second. (Hint:remember the relationship of impulse and change in momentum)
*Tuesday, November 18, 2014 at 4:54pm*

**physics**

Chapter 18, Problem 13 Two point charges are fixed on the y axis: a negative point charge q1 = -26 μC at y1 = +0.17 m and a positive point charge q2 at y2 = +0.35 m. A third point charge q = +9.5 μC is fixed at the origin. The net electrostatic force exerted on the ...
*Tuesday, November 18, 2014 at 4:32pm*

**physics**

Background pertinent to this problem is available in Interactive LearningWare 18.3. A uniform electric field exists everywhere in the x, y plane. This electric field has a magnitude of 5700 N/C and is directed in the positive x direction. A point charge -5.4 × 10-9 C is ...
*Tuesday, November 18, 2014 at 4:31pm*

**physics**

A 2-kilogram ball is accelerated from rest to a speed of 8 m/sec. What is the ball`s change in momentum? Looking for? Given? Relationship?(formula) Solution?
*Tuesday, November 18, 2014 at 3:47pm*

**Physics**

A 8.34kg lump of clay travels east on frictionless ice at a speed of 2.40 m/s. A .170 kg hockey puck travels northward and collides with the clay. After the collision, both objects stick together, and move off at a speed of 2.59 m/s in a direction of 23.9* north of east. What ...
*Tuesday, November 18, 2014 at 3:47pm*

**physics**

An Olympic diver falls from rest from the platform 10m high. At what velocity does the diver hit the water is acceleration in 9.8m/s^2. Do I assume "rest" means a initial velocity of 0? Could the formula be: d= (vf^2-vi^2)/2(a) ? as in d=10, a=9.8 vi=0 vf = √(d...
*Tuesday, November 18, 2014 at 3:28pm*

**physics**

Jake's momentum is 100kg*m/sec when he walks at 2 m/sec. What is his mass?
*Tuesday, November 18, 2014 at 3:26pm*

**Physics**

A glass block has a refractive index of 1.49. What is the critical angle for the block?
*Tuesday, November 18, 2014 at 1:22pm*

**physics**

It has been said that sometimes lead bullets melt upon impact. Assume that a bullet with an initial temperature of 301 K receives 67.9 % of the work done on it by a wall on impact as an increase in internal energy. (The melting point of lead is 601 K, the heat of fusion for ...
*Tuesday, November 18, 2014 at 1:17pm*

**physics**

The R-factor for housing insulation gives the thermal resistance in units of ft2 °F h/BTU. A good wall for harsh climates, corresponding to about 10 in of fiberglass, has R = 39 ft2 °F h/BTU. a) Determine the thermal resistance (in m2 K/W) in SI units. Yanlýþ...
*Tuesday, November 18, 2014 at 1:16pm*

**Physics **

A piece of red glass is heated till it glows in dark.the colour of glowing glass would be?
*Tuesday, November 18, 2014 at 9:58am*

**Physics**

A red flower seen in the light of mercury vapour lamp through a green filter will appear?
*Tuesday, November 18, 2014 at 9:55am*

**physics**

A red flower seen in the light of mercury vapour lamp through a green filter wil appear in what colour?
*Tuesday, November 18, 2014 at 9:36am*

**physics**

Nd/Na = -V.g.hd(beta-beta1)/KT NdNa: No of particules(mole) V: Volume g: gravitational acceleration hd: distance beta: densities(mass/volume) k: Boltzman constant (joules/kelvin) T: absolute temperature(kelvin) volume = L3 gravitational acceleration L/T2 1joule = 1kgm2/S2
*Tuesday, November 18, 2014 at 9:02am*

**Physics**

A 0.50 kg ball is moving with a velocity of 8.0 m/s along a horizontal floor. It hits another ball with a mass of 0.80 kg and moving at 10.0 m/s in the opposite direction. If the first ball bounces back with a velocity of 12 m/s, with what velocity and in what direction will ...
*Tuesday, November 18, 2014 at 7:07am*

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