Thursday

July 30, 2015

July 30, 2015

Number of results: 43,168

**physics**

a projectile is fired from the top of a building with an initial velocity straight upward at 40m/sec. the top of the building is 50 meters above the ground? a) the maximun height of the projectile above the building b) the time for the projectile to reach the top c) the ...
*October 15, 2011 by daniel*

**Physics**

I need help setting up this problem. While standing on the roof of a building, a child tosses a tennis ball with an initial speed of 15 m/s at an angle of 20° below the horizontal. The ball lands on the ground 2.8 s later. How tall is the building? Thank you.
*September 30, 2014 by Edward*

**Physics**

I need help setting up this problem. While standing on the roof of a building, a child tosses a tennis ball with an initial speed of 15 m/s at an angle of 20° below the horizontal. The ball lands on the ground 2.8 s later. How tall is the building? Thank you.
*September 30, 2014 by Edward*

**Maths **

A ball bounces two-thirds of the distance it falls. If it is dropped from a height of 10 meters, how far does it move before hitting the floor for the fourth time?
*October 3, 2012 by ALI *

**physics**

at a ball game consider a baseball of mass m=0.15 that falls directly downward at a speed v=40m/s into the hands of a fan. what impulseft must be supplied to bring the ball to rest? if the ball is stopped in 0.3s, what is the average force of the ball on the catchers hand?
*October 15, 2009 by saba*

**physics**

at a ball game consider a baseball of mass m=0.15 that falls directly downward at a speed v=40m/s into the hands of a fan. what impulseft must be supplied to bring the ball to rest? if the ball is stopped in 0.3s, what is the average force of the ball on the catchers hand?
*October 15, 2009 by Anonymous*

**physics**

at a ball game consider a baseball of mass m=0.15 that falls directly downward at a speed v=40m/s into the hands of a fan. what impulseft must be supplied to bring the ball to rest? if the ball is stopped in 0.3s, what is the average force of the ball on the catchers hand?
*October 15, 2009 by saba*

**geometry**

chung ho is standing on the top of a building that is 135m tall. The angle of depression to the top of the building next door is 71 degrees. The angle to the base of the building is 77 degrees. The buildings are 31m apart. How tall is the other building? thanks for your help.
*March 1, 2012 by Math*

**physics**

A 0.67 kg rock is projected from the edge of the top of a building with an initial velocity of 11.6 m/s at an angle 52 ◦ above the horizontal. Due to gravity, the rock strikes the ground at a horizontal distance of 19.5 m from the base of the building. How tall is the ...
*September 2, 2012 by Noah*

**Physics**

A 0.54 kg rock is projected from the edge of the top of a building with an initial velocity of 13.8 m/s at an angle 59◦ above the horizontal.Due to gravity, the rock strikes the ground at a horizontal distance of 20.3 m from the base of the building.How tall is the ...
*November 29, 2012 by Big Poppa Smurf*

**Physics Repost**

I need help setting up this problem. While standing on the roof of a building, a child tosses a tennis ball with an initial speed of 15 m/s at an angle of 20° below the horizontal. The ball lands on the ground 2.8 s later. How tall is the building? Thank you.
*September 30, 2014 by Edward*

**Physical Science**

Three balls (see below) are dropped simultaneously from the 40th floor of a tall building into the air below. A) In what order will they hit the ground, or will they arrive at the same time? B) Provide an explanation for your answer above. Ball A (softball size; wt= 50 g) Ball...
*January 29, 2012 by Aubree*

**math**

A ball rebounds to one quarter from which it was dropped. approximate the total vertical distance the ball after being dropped from 3ft above the ground ,until it comes to rest
*April 15, 2014 by anna*

**Physics **

A ball is thrown horizontally from the top of a 65 m building and lands 105 m from the base of the building. Ignore air resistance, and use a coordinate system whose origin is at the top of the building, with positive y upwards and positive x in the direction of the throw. 1...
*September 11, 2014 by Lauren HELP *

**physics**

A ball is dropped from an upper floor, some unknown distance above your apartment. As you look out of your window, which is 1.5 m tall, you observe that it takes the ball 0.18 seconds to traverse the length of the window. Determine how high above the top of your window the ...
*January 30, 2015 by ryan*

**physics**

Jack drops a stone from rest off of the top of a bridge that is 24.4 m above the ground. After the stone falls 6.6 m, Jill throws a second stone straight down. Both rocks hit the water at the exact same time. What was the initial velocity of Jill's rock? Assume upward is the ...
*August 30, 2014 by Tracy*

**math**

a ball is dropped from a height of 5m. after each bounce, the ball rises to 45% of its previous height. what the total vertical distance that the ball has travelled after it has hit the ground for for the 6th time? what are the formulas? because the ball bounces twice each time
*November 18, 2008 by tee*

**Trig**

A 60 ft. antenna stands on top of a building, From a point on the ground, the angles of elevation to the top and bottom of the antenna measure 58 and 44 respectively. How tall is the building
*April 5, 2011 by John*

**Physics**

A ball is thrown straight up from the ground with speed . At the same instant, a second ball is dropped from rest from a height , directly above the point where the first ball was thrown upward. There is no air resistance. Question- Find the value of in terms of and so that at...
*May 28, 2010 by Anonymous*

**science**

1.) what energy transformation are taking place when a ball is dropped from 1.0 m, bounces and tries to 0.80 m, bounces again and rises to 0.64m? What is the efficiency of the energy transformations of ball during a bounce?
*August 4, 2014 by chen*

**Physics Classical Mechanics**

A superball of mass m, starting at rest, is dropped from a height hi above the ground and bounces back up to a height of hf. The collision with the ground occurs over a total time tc. You may ignore air resistance. (a) What is the magnitude of the momentum of the ball ...
*October 28, 2013 by Anonymous*

**physics(easy)**

A superball of mass m, starting at rest, is dropped from a height hi above the ground and bounces back up to a height of hf. The collision with the ground occurs over a total time tc. You may ignore air resistance. (a) What is the magnitude of the momentum of the ball ...
*October 24, 2013 by Anonymous*

**physics**

Suppose I throw a ball straight up at an initial speed of 10 m/s. Suppose I'm 2 meters tall (about 6 feet) and the ball leaves my hand at 2 meters from the ground. How fast is it going at its highest point? How fast is it going on its way back down at 2 meters above the ground...
*September 21, 2010 by Sarah*

**physical**

A ball is dropped from the roof a building which is 256m high.The height h of the ball at any instant t is described by h(t)= -16tsqure+256 Find 1)Instantaneous velocity of ball at t= 3sec 2)The time taken by ball to reach the ground level
*June 25, 2015 by Qandeel*

**PHYSICS**

A superball of mass m, starting at rest, is dropped from a height hi above the ground and bounces back up to a height of hf. The collision with the ground occurs over a total time tc. You may ignore air resistance. (a) What is the magnitude of the momentum of the ball ...
*October 24, 2013 by Anonymous*

**PHYSICS**

A superball of mass m, starting at rest, is dropped from a height hi above the ground and bounces back up to a height of hf. The collision with the ground occurs over a total time tc. You may ignore air resistance. (a) What is the magnitude of the momentum of the ball ...
*October 25, 2013 by Anonymous*

**Physics**

Part 1: Two balls (Ball 1 and Ball 2) are released from the top of a tower. Ball 2 is thrown 3.14 seconds after Ball 1 is dropped. Ball 2 is thrown downward with a velocity of 3.49 m/s. Determine how far apart Ball 1 and Ball 2 are after 5.02 seconds from when Ball 1 was ...
*September 12, 2012 by Ashley*

**Physics**

Part 1: Two balls (Ball 1 and Ball 2) are released from the top of a tower. Ball 2 is thrown 3.14 seconds after Ball 1 is dropped. Ball 2 is thrown downward with a velocity of 3.49 m/s. Determine how far apart Ball 1 and Ball 2 are after 5.02 seconds from when Ball 1 was ...
*September 12, 2012 by Ashley*

**college physics**

A small ball of mass m is aligned above a larger ball of mass M = 0.79 kg (with a slight separation), and the two are dropped simultaneously from height h = 2.0 m. (Assume the radius of each ball is negligible relative to h). (a) If the larger ball rebounds elastically from ...
*November 12, 2009 by Steve*

**TRIG Help help help test tommarow**

A TV tower stands on top of the Empire State building. From a point (on the ground) 1150 feet from the base of the building, the angle of elevation to the top of the TV tower is 52 degrees. If the building is 1250 feet tall, what is the length of the TV tower?
*May 22, 2013 by Precious*

**physics**

A ball of mass m=0.25 kg is dropped from rest. What is the speed of the ball after it falls two meters?
*April 22, 2014 by Elle*

**trig**

Question Part Points Submissions Used The angle of elevation to the top of a very tall Building is found to be 7° from the ground at a distance of 1 mi from the base of the building. Using this information, find the height of the building.
*October 2, 2011 by sanam*

**physics**

Two golf balls are thrown with the same speed off the top of a large bridge at the same time. Ball A is thrown straight downward, and Ball B is thrown horizontally off the bridge. Which ball hits the ground first?
*July 29, 2013 by cammi*

**physics**

a ball is dropped off a 20m high building, the ball weights 5 g. how long does it take to hit the ground and what is the instaneous speed of the the ball at each second of it's fall?
*October 17, 2010 by m,ary*

**science**

a ball is dropped from the roof of a building. it takes 10 seconds to reach the ground. find the height of the building.(g=9.8/s square)
*August 8, 2013 by swagster*

**math**

An object dropped from restfrom the top of a tall building falls y=16t^2 feet in the first t seconds. Find the speed of the object at t=3 seconds and confirmalgebraically. The answer is 96 feet/sec but how do i figure it out? cans omeone show me steps? thanks
*September 2, 2009 by cara*

**physics**

A 156 gram 8 ball rolls across a pool table at 2 m/s when it collides with a 7 ball of equal mass rolling in the opposite direction at 1.5 m/s. The 8 ball bounces backwards at 1 m/s. Find the momentum of the 7 ball.
*June 12, 2012 by someone*

**College Algebra**

How long would it take for a ball dropped from the top of a 400 foot building to hit the ground? Round your answer to two decimal places Use gravity formula
*January 25, 2012 by Heather *

**algebra 2**

if a rock is dropped from the top of a 200 ft building, solve for the time it takes for it to hit the ground. (when h=0) hint-initial velocity when dropped is 0
*May 26, 2013 by maddy*

**geometry**

Marta is standing 4ft. Behind a fence 6 inches tall. When she looks over the fence, she can just. See the top of a building. She knows that the building is 32 ft. 6 inches behind the fence. Her eyes are 5 ft. From the ground. How tall is the building?
*March 20, 2014 by Anonymous*

**Physics **

A rock thrown straight up with a velocity of 29 m/s from the edge of a building just misses the building as it comes down. The rock is moving at 44 m/s when it strikes the ground. How tall was the building? The acceleration of gravity is 9.8 m/s Answer in units of m
*September 3, 2012 by Diane*

**physics**

A stone falls from rest from the top of a cliff. A second stone is thrown downward from the same height 3.3 s later with an initial speed of 64.68 m/s. They hit the ground at the same time. The acceleration of gravity is 9.8 m/s2 . How long does it take the first stone to hit ...
*September 19, 2011 by R*

**Physics**

Standing on the top ledge of a 55 m high building you throw a ball straight up with an initial speed of 29 m/s. How long to the nearest second, does it take to hit the ground? Answer after rounding is 7 seconds. The next question is "If the building in the previous problem is ...
*August 26, 2012 by Anonymous*

**Physics**

A ball is dropped from a roof of a building and strikes the ground in 3 seconds. If a second ball is thrown horizontally from the roof, it will hit the ground in:
*September 11, 2014 by Josh*

**Math 10**

Hello, Is there easiest and simplest way to do this question? "A baseball is thrown from the top of a building and falls to the ground below. The height of the baseball above the ground is approximated by the relation h = -5t2 + 10t + 15, where h is the height above the ground...
*April 13, 2014 by Serena*

**physics**

a ball is dropped from the top on an 80-m high building. what speed does the ball have in falling 3.5 s?
*March 30, 2014 by Katie*

**Physics**

King Kong carries Fay Wray up the 321 m tall Empire State Building. At the top of the skyscraper, Fay Wray’s shoe is knocked off with an initial upwards velocity of 5.1 and falls towards the ground. With what final velocity will the shoe be moving when it hits the ground?
*February 16, 2012 by Rachel*

**AP Physics**

A rock thrown straight up with a velocity of 30 m/s from the edge of a building just misses the building as it comes down. The rock is moving at 47 m/s when it strikes the ground. How tall was the building? The accelera- tion of gravity is 9.8 m/s2 . Answer in units of m.
*August 24, 2010 by Alex*

**physics college**

A body is dropped from the rooftop of a building.The body reaches the ground at t= 4.05 from the point of release.How tall is the building?What is the speed of the body just before it reaches the ground?
*November 23, 2011 by thea*

**physics**

Ball A is dropped from the top of a building of height h at the same instant that ball B is thrown vertically upward from the ground. When the balls collide, they are moving in opposite directions, and the speed of A is twice the speed of B. At what height does the collision ...
*August 9, 2014 by Danielle*

**Calculus**

A fence 3 feet tall runs parallel to a tall building at a distance of 3 feet from the building. What is the length of the shortest ladder that will reach from the ground over the fence to the wall of the building. Answer the following: The distance along the ladder to the top ...
*June 18, 2013 by Morgan*

**physics**

A stone is dropped from the roof of a tall building. A person measures the speed of hte stone to be 49 m/s when it hits the ground. What is the height of the building?
*September 18, 2011 by shannon*

**physics**

a ball is dropped from a tower 122.5meters tall. how long does it take the ball to reach the ground?
*October 5, 2011 by m kay*

**physics**

You stand at the top of a cliff while your friend stands on the ground below you. You drop a ball from rest and see that it takes 0.90 for the ball to hit the ground below. Your friend then picks up the ball and throws it up to you, such that it just comes to rest in your hand...
*January 30, 2011 by SAM*

**science**

Science Experiment Determine a mathematical modelwhich describes the height of a ball in terms of th number of bounces after it has been droped from a given height. If a ball that bounces like a tenniis ball, is dropped from a given height, then it will bounce to a height less...
*October 21, 2009 by Nicholas*

**science**

A ball is thrown upward from the ground with an initial speed of 16.0 m/s; at the same instant, another ball is dropped from a building 12 m high. After how long will the balls be at the same height above the ground?
*January 22, 2015 by Leah*

**trigo**

the L and C State building is 1,250 m tall. What is the angle of elevation of the top from a point on the ground 1,760 m from the base of the building?
*July 31, 2010 by trigofunctions*

**trigo**

The L and C State Building is 1,250 m tall. What is the angle od elevation of the top from a point on the ground 1,760 m from the base of the building?
*August 1, 2010 by trigofunctions*

**physics**

two balls are dropped to the ground from different heights. one ball is dropped 2s after the other but they both strike the ground at the same time, 5s after the first is dropped. what is the difference in height from which they are dropped? from what height was the first ball...
*June 14, 2011 by pavatharani*

**Physics**

A ball dropped from rest on to horizontal ground 20m between rebounds with 3/4 of the velocity with which it hits the ground find time that elapses between the first and second in part of the ball with the ground
*October 2, 2011 by Anonymous*

**Physics**

You throw a ball straight down from an apartment balcony to the ground below. The ball has an initial velocity of 4.50 m/s, directed downward, and it hits the ground 2.04 s after it is released. Find the height of the balcony.
*February 24, 2010 by Delilah*

**physics**

You throw a ball straight down from an apartment balcony to the ground below. The ball has an initial velocity of 5.25 m/s, directed downward, and it hits the ground 1.94 s after it is released. Find the height of the balcony.
*September 13, 2011 by Nour *

**Physics**

You throw a ball straight down from an apartment balcony to the ground below. The ball has an initial velocity of 5.20 m/s, directed downward, and it hits the ground 2.10 s after it is released. Find the height of the balcony.
*January 31, 2012 by Haze*

**Physics**

A ball initially at rest is dropped from a window 18.6 m off the ground. How long does it take for the ball to reach the ground? Round your answer to 2 decimal places.
*November 21, 2010 by Patel*

**physics**

A body is dropped from the rooftop of the building.The body reaches the ground at t= 4.05 from the point of release.how tall is the building?what is the speed of the body just before it reaches the ground?
*November 23, 2011 by thea*

**Physics**

A ball, dropped from rest, cover 2/7 of the distant to the ground in the last 2 seconds of its fall. From what height was the ball dropped? What was the total time of the fall?
*October 11, 2009 by Robert C*

**Physics**

A ball is thrown straight up from the ground with speed v_0. At the same instant, a second ball is dropped from rest from a height H, directly above the point where the first ball was thrown upward. There is no air resistance. Find the value of H in terms of v_0 and g so that ...
*May 28, 2010 by Anonymous*

**Physics**

A 0.030-kg bullet is fired straight up at a falling wooden block that has a mass of 5.0 kg. The bullet has a speed of 700 m/s when it strikes the block. The block originally was dropped from rest from the top of a building and had been falling for a time t when the collision ...
*October 24, 2010 by Xavier*

**Physics**

A 0.012-kg bullet is fired straight up at a falling wooden block that has a mass of 5.0 kg. The bullet has a speed of 670 m/s when it strikes the block. The block originally was dropped from rest from the top of a building and had been falling for a time t when the collision ...
*January 11, 2011 by Tom Atlus*

**Physics**

A 0.014 kg bullet is fired straight up at a falling wooden block that has a mass of 4.0 kg. The bullet has a speed of 760 m/s when it strikes the block. The block originally was dropped from rest from the top of a building and had been falling for a time t when the collision ...
*October 22, 2012 by Elizabeth*

**Physics**

A 0.0122-kg bullet is fired straight up at a falling wooden block that has a mass of 2.17 kg. The bullet has a speed of 813 m/s when it strikes the block. The block originally was dropped from rest from the top of a building and had been falling for a time t when the ...
*October 13, 2013 by Briana*

**Physics!**

A 0.0124-kg bullet is fired straight up at a falling wooden block that has a mass of 3.96 kg. The bullet has a speed of 756 m/s when it strikes the block. The block originally was dropped from rest from the top of a building and had been falling for a time t when the ...
*October 19, 2014 by Sanz*

**physics**

a ball is dropped from a height of 10 meters.if the energy of the ball is reduced by 40% after striking the ground,how high can the ball bounce back?
*February 16, 2012 by sherry*

**calculus**

A fence 8 feet tall stands on level ground and runs parallel to a tall building. If the fence is 1 foot from the building, find the shortest ladder that will extend from the ground over the fence to the wall of the building.
*October 11, 2012 by Erica*

**Physics**

A. You can use any coordinate system you like in order to solve a projectile motion problem. To demonstrate the truth of this statement, consider a ball thrown off the top of a building with a velocity at an angle θ with respect to the horizontal. Let the building be 50.0...
*September 9, 2011 by Awonah*

**physics**

A man stands at the top of a 27-m high building and throws a penny straight downward. If the penny has an initial velocity of -3.9 m/s, what is the velocity of the penny in m/s when it hits the ground?
*September 9, 2014 by Carissa*

**Calculus**

A fence 5 feet tall runs parallel to a tall building at a distance of 2 feet from the building. We want to find the the length of the shortest ladder that will reach from the ground over the fence to the wall of the building. Here are some hints for finding a solution: Use the...
*July 17, 2013 by J*

**physics**

A ball is dropped from rest off a 27 m building.What is the maximum speed that the ball will reach?
*September 24, 2012 by Brayden*

**algebra**

A ball falls from the top of a roof 320 feet above the ground. The formula h = -16t2 + 16t + 320 described the height of the ball above the ground, h, in feet, t seconds after the fall begins. How long will it take the ball to strike the ground?
*May 16, 2010 by Anonymous*

**Science**

A ball is dropped from a height of 10m .If the energy of ball reduces by 40% after striking the ground, how much high can the ball bounce back?
*February 25, 2012 by Sharma*

**science**

A ball is dropped from a height of 10 m. If the energy of the ball reduces by 40% after striking the ground, how much high can the ball bounce back? (g=10m/s2)
*February 22, 2015 by Anonymous*

**physics**

1.In a cathode ray tube, electrons are accelerated from rest by a constant electric force of magnitude 6.56 x 10*-17 N during the first 1.87 cm of tube's length; then they move at essentially constant velocity another 45.0 cm before hitting the screen. Find the speed of the ...
*September 24, 2008 by Sandhya*

**Physical Science**

Explain the energy conversions that occur as a basketball falls, hits the ground, and bounces back up. Ignore frictional forces.
*February 2, 2014 by Alex*

**geometry**

at a distance of 20m from a building, a person who is 3 m tall looks up at an angle of 25 degrees to see the top of the building. how tall is the building to the nearest meter?
*May 21, 2013 by Alia*

**Physics**

A baseball is released at rest from the top of the washington Monument. It hits the ground after falling for 6.0 s. What was the height from which the ball was dropped? (g=9.8 m/s2 and assume air resistance is negligible)
*December 3, 2010 by Jesse*

**Physics **

A ball is tossed from an upper-story window of a building. The ball is given an initial velocity of 8.15 m/s at an angle of 18.5o below the horizontal. It strikes the ground 3.30 s later. How far horizontally from the base of the building does the ball strike the ground? What ...
*February 7, 2012 by Chloe *

**Physics**

You are standing at the foot of the Bank of America building in San Francisco, which is 52 floors (237 m) high. You launch a ball straight up in the air from the edge of the foot of the building. The initial vertical speed is 70 m/s. a. How high up does the ball go? b. How ...
*August 26, 2012 by Sara*

**math**

A tree is struck by lightning. The top part breaks and falls to the ground. The part of the tree still standing is 30 feet tall and the top part that hit the ground is 40 feet from the base of the tree. How tall was the tree originally?
*January 10, 2013 by Jess*

**Physics**

A 3 kg ball is dropped from the top of a cliff. At the same time, a 9 kg ball is fired straight down from the top of the cliff. Ignoring air resistance, what can we say about their accelerations after being released?
*November 4, 2010 by Zaphod*

**Physics **

A billiard ball with mass 0.210 kg has a speed of 5.2 m/s and collides completely inelastically with another ball of the same size and mass. I understood the first part of the problem I just need help solving the second part. Another billiard ball traveling at 6.25 m/s ...
*November 14, 2013 by Leslie*

**physics**

A ball is dropped from a tall building What is its acceleration What does the acceleration tell us about the velocity of the ball
*May 3, 2012 by lisa*

**Calculus**

A fence 5 feet tall runs parallel to a tall building at a distance of 7 feet from the building. What is the length of the shortest ladder that will reach from the ground over the fence to the wall of the building? [Hint: Determine the length of a ladder that touches the ...
*June 22, 2009 by Z32*

**physics**

A 3.60 kg ball is dropped from the roof of a building 184.8 m high. While the ball is falling to earth, a horizontal wind exerts a constant force of 12.1 N on the ball. How long does it take to hit the ground? (acceleration of gravity = 9.81 m/s^2)
*November 6, 2009 by Ash*

**physics**

A 4.05 kg ball is dropped from the roof of a building 171.4 m high. While the ball is falling to Earth, a horizontal wind exerts a constant force of 12.5 N on the ball. How long does it take to hit the ground? The acceleration of gravity is 9.81 m/s^2.
*November 6, 2010 by Harmonie*

**physics**

A 3.61 kg ball is dropped from the roof of a building 152.5 m high. While the ball is falling to Earth, a horizontal wind exerts a constant force of 11.6 N on the ball. How long does it take to hit the ground? The acceleration of gravity is 9.81 m/s^2
*December 17, 2010 by john*

**science math practice **

a 60.0-kg person walks from the ground to the roof of a 74.8-m-tall building. how much gravitational potential energy does she have at the top of the building?
*March 8, 2012 by celeste *

**Physics**

Ball A leaves the edge of a level table with speed Va and falls to the floor. At the instant ball A leaves the table edge, another identical ball, B, is released from rest at the height of the table top and also falls to the floor. It is observed that the balls reach the floor...
*October 5, 2010 by Balthazar*

**Math - Trig**

From the foot of a building I have to look upwards at an angle of 22degrees to sight the top of a tree. From the top of a building, 150 meters above ground level, I have to look down at an angle of depression of 50degrees to look at the top of the tree. a. How tall is the tree...
*December 14, 2013 by McKenna Louise*

**physics**

I'm suppose to draw velocity time and acceleration time graph for a rocket that is launched vertically into the air and falls back down to its initial height. We are to assume that x axis is up. So would I draw an curved figure like a downward parabola or a straight vertical ...
*September 5, 2011 by Jennifer*

**Trigonometry**

From the foot of a building I have to look upwards at an angle of 22degrees to sight the top of a tree. From the top of a building, 150 meters above ground level, I have to look down at an angle of depression of 50degrees to look at the top of the tree. a. How tall is the tree...
*December 15, 2013 by Marie Ashley*