Friday

February 12, 2016
**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 by Anonymous*

**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 by Kris*

**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 by Vanessa Ozuna*

**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 by Vanessa Ozuna*

**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 by Shannelle*

**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 by Maddie*

**Physics-**

How can anything accelerate if every force has and equal and opposite counterpart?
*Thursday, November 20, 2014 by Devynn Austin*

**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 by Mechai*

**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 by sule*

**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 by jlynn*

**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 by rayan*

**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 by Alejandra*

**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 by Paul*

**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 by Ann*

**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 by Ann*

**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 by Maria*

**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 by ginny*

**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 by leah*

**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 by Anonymous*

**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 by Anonymous*

**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 by Anonymous*

**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 by Dane*

**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 by Dane*

**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 by Dane*

**physics**

how long the ball takes to reach the groud
*Thursday, November 20, 2014 by erna*

**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 by marvellous*

**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 by namabia*

**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 by Help*

**Physics help please**

A 0.504 m length of conducting wire carrying a current of 62.1 A is?
*Wednesday, November 19, 2014 by alex*

**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 by alex*

**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 by Hershey*

**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 by Rose*

**physics**

what should the ratio of mass to volume be when considering the flight of a hot air balloon.
*Wednesday, November 19, 2014 by kaitlyn*

**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 by Thor*

**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 by mary*

**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 by Peggy*

**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 by Jason*

**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 by Alex*

**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 by Rose*

**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 by Rose*

**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 by Jason*

**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 by Jason*

**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 by Jason*

**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 by namabia*

**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 by namabia*

**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 by namabia*

**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 by wallacenjovu *

**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 by David*

**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 by Michelle*

**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 by Sam*

**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 by Shannelle*

**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 by Wendy*

**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 by stephan*

**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 by bill*

**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 by Anonymous*

**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 by Anonymous*

**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 by Anonymous*

**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 by P*

**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 by billybob*

**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 by Layla*

**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 by Help*

**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 by lexi*

**physics**

with a cart of unknown mass, could you still determine whether its total energy is conserved? explain your reasoning
*Tuesday, November 18, 2014 by Anonymous*

**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 by mya*

**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 by namabia*

**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 by namabia*

**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 by mya*

**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 by Blue*

**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 by jesse*

**physics**

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

**Physics**

A glass block has a refractive index of 1.49. What is the critical angle for the block?
*Tuesday, November 18, 2014 by Carl*

**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 by mehmet kaya*

**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 by mehmet kaya*

**Physics **

A piece of red glass is heated till it glows in dark.the colour of glowing glass would be?
*Tuesday, November 18, 2014 by Nivetha shree.j*

**Physics**

A red flower seen in the light of mercury vapour lamp through a green filter will appear?
*Tuesday, November 18, 2014 by Nivetha shree.j*

**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 by Nivetha shree.j*

**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 by lamp*

**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 by Johnrey*

**physics**

In an experiment to verify Newton's law of cooling, the temperature of hot water in a calorimeter T/oC is plotted against time t/min. Which of the following is true about the graph? a. the graph is linear and parallel to the T-axis b. the slope of the graph is positive c. ...
*Tuesday, November 18, 2014 by Sam*

**physics**

a block is pushed up against the wall. Let the mass of the block be m = 2.8 kg, the coefficient of kinetic friction between the block and the wall be µ = 0.56, and θ = 61◦ . Suppose F = 73 N. The acceleration of gravity is 9.8 m/s 2 Find the force of friction...
*Tuesday, November 18, 2014 by Anonymous*

**physics**

In a house the temperature at the surface of a window is 20.1 °C. The temperature outside at the window surface is 2.72 °C. Heat is lost through the window via conduction, and the heat lost per second has a certain value. The temperature outside begins to fall, while ...
*Monday, November 17, 2014 by Anonymous*

**physics**

A copper pipe with an outer radius of 0.010 m runs from an outdoor wall faucet into the interior of a house. The temperature of the faucet is 3.3°C, and the temperature of the pipe, 3.0 m from the faucet, is 25°C. In fifteen minutes, the pipe conducts a total of 270 J ...
*Monday, November 17, 2014 by Anonymous*

**physics**

An express subway train passes through an underground station. It enters at t = 0 with an initial velocity of 23.5 m/s and decelerates at a rate of 0.150 m/s2 as it goes through. The station in 215 m long. (a) How long is the nose of the train in the station? (b) How fast is ...
*Monday, November 17, 2014 by mathew*

**physics**

Save Two children hang by their hands from the same tree branch. The branch is straight, and grows from the tree trunk at an angle of 27 degrees above the horizontal. One child, with a mass of 39 kg is hanging 1.50 m along the branch from the tree trunk. The other child, with...
*Monday, November 17, 2014 by george*

**Physics**

A motor pushes a boat through the water with the force of 2100 N; the water creates a resistance force of 1800 N. What is the acceleration of 1200 kg boat? (Do I use force equals mass times acceleration? 2100=1200a) If it starts from rest how far will it move in 10 seconds? (...
*Monday, November 17, 2014 by Jay*

**physics**

Find the force (in newton) required to lift a mass of 26 kg load with a wheelbarrow (2nd class lever) with the load at 0.75 m from the fulcrum and being lifted at 1.7 m from the fulcrum, assuming ideal conditions.
*Monday, November 17, 2014 by kody*

**Physics**

A woman is swimming when she hears the underwater sound wave from an exploding ship across the harbor. She immediately lifts her head out of the water. The sound wave from the explosion propagating through the air reaches her 4.00 s later. How far away is the ship? Assume that...
*Monday, November 17, 2014 by Malorie*

**Physics**

A woman is swimming when she hears the underwater sound wave from an exploding ship across the harbor. She immediately lifts her head out of the water. The sound wave from the explosion propagating through the air reaches her 4.00 s later. How far away is the ship? Assume that...
*Monday, November 17, 2014 by Malorie*

**physics**

A railway flat car is rushing along a level frictionless track at a speed of 45m/s. Mounted on the car and aimed forward is a cannon that fires 65 kg cannon balls with a muzzle speed of 625m/s. The total mass of the car, the cannon, and the large supply of cannon balls on the ...
*Monday, November 17, 2014 by togo*

**Chemistry Physics**

How many Btu of heat are required to melt 33.0 lb of ice at 32°F and to raise the temperature of the melted ice to 72°F?
*Monday, November 17, 2014 by Ben*

**College Physics**

A 1.45kg mass oscillates according to the equation x=0.650cos8.10t, where x is in meters and t is in seconds.Determine the amplitude, frequency, total energy, and the potential and kinetic energy at x=0.370
*Monday, November 17, 2014 by Saya*

**physics**

A point mass m starts from rest and slides down the surface of a frictionless solid sphere of radius r. Find the angle at which the mass flies off the sphere
*Monday, November 17, 2014 by sns*

**physics**

A circus performer decides to take his human cannonball act to the extreme. After being shot from a cannon, he soars over three ferris wheels and into a net. Assume that he is launched with a speed of 26.5m/s at an angle of 53.0 degrees, what angle does he make with the ...
*Monday, November 17, 2014 by Hakeem*

**Physics**

a backpack has a massof 8kg.it is lifted and given 54.9 joules of gravitstional potential energy. how high is it lifted? accelerationdue to gravity is g=98 m/s^2.
*Monday, November 17, 2014 by Anonymous*

**Physics **

AN astronaut on the Moon has a mass (including his spacesuit and equipment) of 180 kg. the acceleration due to gravity on the Moon is 1.6 m/s2 (seconds squared). a) calculate his weight on the moon. the astronaut climbs 100m to the top of the crater . b) by how much does his ...
*Monday, November 17, 2014 by Mariam*

**physics**

Objects of masses m1 = 4.00 kg and m2 = 9.00 kg are connected by a light string that passes over a frictionless pulley as in Figure P4.48. The object m1 is held at rest on the floor, and m2 rests on a fixed incline of θ = 36.0°. The objects are released from rest, and...
*Sunday, November 16, 2014 by DeShawn*

**physics**

A solid disk rotates in the horizontal plane at an angular velocity of 0.040 rad/s with respect to an axis perpendicular to the disk at its center. The moment of inertia of the disk is 0.13 kg·m2. From above, sand is dropped straight down onto this rotating disk, so ...
*Sunday, November 16, 2014 by bob*

**Physics**

For the situation: "A moving crate slides to a halt on a rough surface" Does temperature increase, decrease, or not change? Are work and heat positive, negative, or zero? Does thermal energy increase, decrease, or not change? My answer key says temperature increases...
*Sunday, November 16, 2014 by Courtney*

**Thank Jiskha tutors**

I really appreciate all that you tutors do for us, I know we may be a bit demanding sometimes XD but we really love how you guys are always there to help us out. Coming from experience, I've had some past teachers that aren't as willing to help us when we do not ...
*Sunday, November 16, 2014 by Andrew*

**physics**

What is the kinetic energy in MeV of a π–meson that lives 1.80×10-16 s as measured in the laboratory, and 0.840×10-16 s when at rest relative to an observer, given that its rest energy is 135 MeV?
*Sunday, November 16, 2014 by Tim*