Friday

July 1, 2016
Number of results: 160,814

**Math**

An airplane is heading due south at a speed of 590km/h. If a wind begins blowing from the southwest at a speed of 65.0km/h (average). Calculate magnitude of the plane's velocity, relative to the ground. Calculate direction of the plane's velocity, relative to the ground. ...
*September 12, 2009 by Anne*

**physics**

Olympic champion Justin gaitlin set a new world record for 100.0 m sprint at the last lympics by clocking 9.86 s for the race.Calculate a)His average speed for the race b)Assuming that he accelerated uniformly for the first 4.86 s after taking off the blocks to reach a maximum...
*September 24, 2007 by JohnX*

**physics**

Olympic champion Justin gaitlin set a new world record for 100.0 m sprint at the last lympics by clocking 9.86 s for the race.Calculate a)His average speed for the race b)Assuming that he accelerated uniformly for the first 4.86 s after taking off the blocks to reach a maximum...
*September 24, 2007 by Sam*

**math**

The train slows down uniformly from a speed of 50m/s to a speed of 10m/s in a time of 20sec,During the next 30sec,it accelerates uniformly to a speed of u metres/sec.calculate the retardation from t=0 to t=20?
*May 3, 2013 by Meggy lep*

**Physics**

A sky diver of mass 80.0 ks jumps from a slow-moving aircraft and reaches a terminal speed of 50.0 m/s. a) What is the acceleration of the sky diver when her speed is 30.0 m/s? What is the drag force on the diver when her speed is b) 50.0 m/s? c) 30.0 m/s? If you assume drag ...
*March 1, 2007 by Jean*

**physics**

A tennis player moves back and forth along the baseline while waiting for her opponent to serve, producing the position-versus-time graph shown in the figure. (The vertical axis is marked in increments of 1 m and the horizontal axis is marked in increments of 4 s.) (a) Without...
*October 3, 2012 by Anonymous*

**math**

A motorist travelling at a steady speed of 120km/h covers a section of the highway in 30min. After a speed limit is imposed he finds that when travelling at the maximum speed allowed he takes 20 min. longer than before to cover the same section. Calculate the speed limit.
*November 30, 2012 by Lindsay*

**physics**

1. A student is dragging a 5 kg box along the floor. He pulls on the rope with a 25 Newton force. The rope is 37 degrees above horizontal. As the box slides 10 meters, it goes from a speed of 3 m/s to a speed of 7 m/s. a.) calculate the normal force on the box b.) calculate ...
*January 12, 2011 by Energy*

**Math**

Marie traveled to work (7km) in 25 minutes. What was her speed? I got 16.8km/h but my teacher said it's 28km/h and I have no idea how he got that. Also, how do you calculate average speed when there's more than one speed? (this is just for the next question)
*June 13, 2016 by Emily*

**math**

. A ship leaves an island (5°N, 45° E) and sails due east for 120 hours to another island. Average speed of the ship is 27 knots. (a) Calculate the distance between the two islands (i) In nautical miles (ii) In kilometers (b) Calculate the speed of the ship in kilometers per ...
*March 12, 2015 by kudu*

**math**

A ship leaves an island (5°N, 45° E) and sails due east for 120 hours to another island. Average speed of the ship is 27 knots. (a) Calculate the distance between the two islands (i) In nautical miles (ii) In kilometers (b) Calculate the speed of the ship in kilometers per hour
*April 30, 2015 by kudu*

**science/math**

A car travels up a hill at a constant speed of 45 km/h and returns down the hill at a constant speed of 70 km/h. Calculate the average speed for the round trip.
*September 24, 2011 by Jonathan*

**math**

The distance from TDC (top dead centre) for the pin is given by x when the crank is at angle . Hence : i) Give an equation for x in terms of the other variables (r, L and ). ii) If the crank rod is rotating at a constant value of ω calculate the speed of ...
*May 17, 2011 by Karl Haxell*

**Physics**

The speed time graph shows the motion of a car over a period of 40 seconds. a. describe the motion of the car between: 1.) O and A - The car is traveling at constant speed from 0 to 20 m/s. 2.) A and B - The car is at rest for 20 seconds. 3.) B and C - The car is decelerating ...
*February 5, 2013 by RR*

**Physics**

The speed time graph shows the motion of a car over a period of 40 seconds. a. describe the motion of the car between: 1.) O and A - The car is traveling at constant speed from 0 to 20 m/s. 2.) A and B - The car is at rest for 20 seconds. 3.) B and C - The car is decelerating ...
*February 5, 2013 by RR*

**Physics **

You are driving south on a highway at 24.0 m/s (approximately 54 mi/h) in a snowstorm. When you last stopped, you noticed that the snow was coming down vertically, but it is passing the windows of the moving car at an angle of 26.6° to the horizontal. Calculate the speed of ...
*February 5, 2012 by Jeremy *

**physics**

A train travel some distance with a speed of 30km/hr and return with a speed of 45km/hr. Calculate average speed.
*June 20, 2013 by Anonymous*

**physics**

A train travel some distance with a speed of 30km/hr and return with a speed of 45km/hr. Calculate average speed.
*June 20, 2013 by Anonymous*

**physics**

A train travel some distance with a speed of 30km/hr and return with a speed of 45km/hr. Calculate average speed.
*June 20, 2013 by Anonymous*

**physics**

A train travel some distance with a speed of 30km/hr and return with a speed of 45km/hr. Calculate average speed.
*June 20, 2013 by Anonymous*

**phys**

An airplane is heading due south at a speed of 590 km/h. If a wind begins blowing from the southwest at a speed of 65.0 km/h (average). Calculate magnitude of the plane's velocity, relative to the ground. Calculate direction of the plane's velocity, relative to the ground. ...
*September 15, 2009 by physics*

**physics**

if co-efficient of friction between tyre and road is 0.5, what is smallest radious at which car turn on a horizontal road when its speed is 30 km/hr? 2.Q calculate angular speed of how hand of a clock? 3.Q A what angle must cut rack with a bend of 250m banked for safe running ...
*September 27, 2010 by vishal*

**math**

a train travels 68 km at an average speed of 51 km/h. it then travels another 20 km at an average speed of 40 km/h before reaching its destination. calculate the average speed of whole journey?
*April 26, 2014 by owais*

**math**

A car takes 3 hours to travel 3km at a constant speed on an open road. Calculate the speed of the car
*September 11, 2011 by Anonymous*

**physics**

A disk rotates about its central axis starting from rest and accelerates with constant angular acceleration. At one time it is rotating at 7 rev/s. 55 revolutions later, its angular speed is 21 rev/s. (a) Calculate the angular acceleration. (b) Calculate the time required to ...
*March 11, 2007 by winterWX*

**physics**

Calculate the magnitude of the linear momentum for the following cases. (a) a proton with mass 1.67 10-27 kg, moving with a speed of 4.00 106 m/s (b) a 16.5 g bullet moving with a speed of 270 m/s (c) a 70.5 kg sprinter running with a speed of 12.5 m/s (d) the Earth (mass = 5....
*July 7, 2008 by Elisa*

**physics**

A 5.40 Kg package slides 1.47 meters down a long ramp that is inclined at 11.6 degress below the horizontal. The coefficient of kinetic friction between the package and the ramp is = 0.313. Calculate the work done on the package by friction. Calculate the work done on the ...
*December 3, 2012 by clariza gonzalez*

**math-calculus**

a plane flew from red deer to winnipeg, flying distance of 1260 km. on the return journey, due to a strong head wind, the plane travelled 1200 km in the same time it took to complete the outward journey. on the outward journey, the plane be able to maintain an average speed ...
*January 8, 2012 by Shreya*

**Science - Waves - Sci. Notation**

I know that the formula to calculate the speed of light is c=fλ. F is the frequency, c is the speed, and λ is the wavelength. So how do I calculate the wavelength of a purple light with a frequency of 750 * 10^12 HZ. Frequency is measured in HZ. The speed is measured...
*January 31, 2013 by Jamia*

**Physics**

Suppose you observe your friend (mass 66.6 kg) stand at the very edge of a motionless merry-go-round (modelled as a thin disk with moment of inertia 5.7 kg m 2). At some point, your friend walks around and along the edge at a speed 1.4 m/s perfectly tangent to the edge at all ...
*April 22, 2016 by Santhiya *

**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...
*January 27, 2015 by Sally*

**physics**

When the Sun is directly overhead, a hawk dives toward the ground with a constant velocity of 4.80 m/s at 50.5° below the horizontal. Calculate the speed of her shadow on the level ground. What i have done: x= rcos(theta) x=4.80m/s*cos(309.5) x=3.05m y=rsin(theta) y=4.80m/s*...
*September 11, 2014 by Gaby*

**physics**

A car moving with an initial speed v collides with a second stationary car that is 50.7 percent as massive. After the collision the first car moves in the same direction as before with a speed that is 33.2 percent of the original speed. Calculate the final speed of the second ...
*March 26, 2014 by Erin*

**Math**

The stopping distance d of a car in feet is related to the speed in mph by the equation d(s)=.02s^2+1.1s Calculate the speed when your stopping distance is: 1.) 51ft 2.) 315.12ft
*February 25, 2012 by Devin*

**Physics**

An object with mass 3.0 kg is executing simple harmonic motion, attached to a spring with spring constant k =210 N/m. When the object is 0.23 m from its equilibrium position, it is moving with a speed of 0.72 m/s. (a) Calculate the amplitude of the motion. m (b) Calculate the ...
*June 12, 2014 by Garrett*

**Math**

Mr. Njinga cycled a distance of 42km from his village. On his return journey he increased his speed by 2km/h and took half an hour less. Calculate the average speed on the journey from his village.
*March 3, 2016 by Christopher*

**Maths**

The distance from TDC (top dead centre) for the pin is given by x when the crank is at angle . Hence : i) Give an equation for x in terms of the other variables (r, L and ). ii) If the crank rod is rotating at a constant value of ω calculate the speed of ...
*May 17, 2011 by Karl Haxell*

**Physics**

A 2.00 kg box slides down a rough incline plane from a height h of 1.99 m. The box had a speed of 2.77 m/s at the top and a speed of 2.34 m/s at the bottom. Calculate the mechanical energy lost due to friction (as heat, etc.) If I were to calculate the energy lost, it would be...
*September 30, 2015 by Ronnie*

**Physics**

1. A person runs 800. m at an average speed of 6.00 m/s and then the next 800. m at an average speed of 8.00 m/s. Calculate (a) the total time of travel and (b) the average speed. 2. A boy kicked a can horizontally from a 6.5 m high rock with a speed of 4.0 m/s. How far from ...
*June 18, 2014 by Piper*

**physics**

A vehicle with a mass of 2 tons travels on a horizontal road at a speed of 126km/h.The driver notices a donkey at the side of the road and decides to reduce speed. The brakes are applied and the vehicle slows down to 72km/h after 5 seconds. Calculate the distance travelled ...
*March 6, 2013 by leslie*

**Physics**

A little red wagon with mass 7.0kg moves in a straight line on a frictionless horizontal surface. It has an initial speed of4.00 m/s and then is pushed 3.0m in the direction of the initial velocity by a force with a magnitude of 10.0 N a.) Use the work-energy theorem to ...
*October 15, 2012 by Frankie*

**Physics**

A little red wagon with mass 7.0kg moves in a straight line on a frictionless horizontal surface. It has an initial speed of4.00 m/s and then is pushed 3.0m in the direction of the initial velocity by a force with a magnitude of 10.0 N a.) Use the work-energy theorem to ...
*October 15, 2012 by Frankie*

**Physics**

Force F causes displacement d of a 20-Kg object starting from rest along a frictionless path. F= 10 N i + 50 N j + 15 N k and d= 10 m i + 60 m k A) Calculate the work done by the force. B) Calculate the angle between the vectors F and d. C) Calculate the final speed of the ...
*April 22, 2009 by Sandhya*

**physics**

In order to convert a tough split in bowling, it is necessary to strike the pin a glancing blow as shown in the figure. Assume that the bowling ball, initially traveling at 15.0 m/s, has four times the mass of a pin and that the pin goes off at 75° from the original direction ...
*October 20, 2011 by kago*

**physics**

A softball of mass 0.220 kg that is moving with a speed of 5.5 m/s (in the positive direction) collides head-on and elastically with another ball initially at rest. Afterward it is found that the incoming ball has bounced backward with a speed of 3.9 m/s. (a) Calculate the ...
*January 10, 2010 by Anonymous*

**Physics**

You are standing on a 50m cliff and throw a ball upwards at 8.2m/s - calculate the maximum height the ball will reach - calculate the time it will take the ball to return where it started - calculate the speed of the ball when it hits the ground. Please help
*September 14, 2015 by Jay*

**physics**

a car travel 100 km at speed of 60 km /h. Calculate the average speed of the journey.
*July 9, 2014 by manpreet sharma langiania*

**physics**

A car moving with an initial speed v collides with a second stationary car that is 46.0 percent as massive. After the collision the first car moves in the same direction as before with a speed that is 37.7 percent of the original speed. Calculate the final speed of the second...
*March 24, 2014 by Sami*

**Chemistry**

A bumblebee flies with a ground speed of 15.2 m/s. Calculate its speed in miles per hour.
*February 9, 2015 by Aerial *

**Maths**

the speed of light is 3 * 10^ 8m/s. Jupiter is 778 million km from the sun. Calculate the number of minutes it takes for sunlight to reach Jupiter ? A star is 300 lights away from Earth. If the speed of light is 3 * 10^5 km/s. calculate the disatance from the star to Earth. ...
*November 26, 2007 by YOYO*

**physics - PLEASE HELP**

A softball of mass 0.220 kg that is moving with a speed of 6.5 m/s (in the positive direction) collides head-on and elastically with another ball initially at rest. Afterward it is found that the incoming ball has bounced backward with a speed of 4.8 m/s. (a) Calculate the ...
*December 10, 2009 by Anonymous*

**Physics**

Calculate the final speed of a skier who skis down a 70.8 m high hill, if her initial speed is 2.18 m/s
*February 9, 2015 by Jessy*

**physics**

A cyclist enters a curve of 30 m radius at a speed of 12 m s-1. He applies the brakes and decreases his speed at a constant rate of 0.5 m s-2. Calculate the cyclist’s centripetal (radial) [3 marks] and tangential [15 marks] accelerations when he is travelling at a speed of 10 ...
*February 28, 2012 by alex*

**Physics**

A car travels up a hill at a constant speed of 33 km/h and returns down the hill at a constant speed of 60 km/h. Calculate the average speed (in km/h) for the round trip.
*January 16, 2011 by Ethan*

**physics**

A car travels up a hill at a constant speed of 45 km/h and returns down the hill at a constant speed of 70 km/h. Calculate the average speed for the round trip.
*September 22, 2011 by Jonoathan*

**physics**

A car travels up a hill at a constant speed of 45 km/h and returns down the hill at a constant speed of 70 km/h. Calculate the average speed for the round trip.
*September 22, 2011 by Jonoathan*

**physics**

A car travels up a hill at a constant speed of 45 km/h and returns down the hill at a constant speed of 70 km/h. Calculate the average speed for the round trip.
*September 22, 2011 by Jonoathan*

**Physics**

Car travels up hill at a constant speed of 50 km/h and returns down the hill at a constant speed of 65 km/h. Calculate the avg speed for the round trip in km/h.
*September 22, 2011 by JP*

**Physics**

A softball of mass 0.200 kg that is moving with a speed of 8.2 m/s collides head-on and elastically with another ball initially at rest. Afterward the incoming softball bounces backward with a speed of 3.9 m/s. 1. Calculate the velocity of the target ball after the collision. ...
*November 12, 2009 by Anonymous*

**physics**

Assuming that the speed of sound at a certain altitude is 330m/s calculate the speed of an airplane that is travelling at (A) mach 0.70
*June 4, 2012 by Melissa*

**physics**

Assuming that the speed of sound at a certain altitude is 330m/s calculate the speed of an airplane that is traveling at match 4.2 ?
*June 6, 2012 by Melissa*

**Calculus/Vectors**

An airplane heads due south with an air speed of 480km/h. Measurements made from the ground indicate that the plane's ground speed is 528km/h at 15 degrees east of south. Calculate the wind speed.
*May 2, 2011 by Anonymous*

**physics**

A softball of mass 0.220 kg that is moving with a speed of 4.0 m/s (in the positive direction) collides head-on and elastically with another ball initially at rest. Afterward the incoming softball bounces backward with a speed of 1.8 m/s. a) Calculate the velocity of the ...
*May 30, 2011 by Nick*

**physics**

A softball of mass 0.220 kg that is moving with a speed of 4.0 m/s (in the positive direction) collides head-on and elastically with another ball initially at rest. Afterward the incoming softball bounces backward with a speed of 1.8 m/s. a) Calculate the velocity of the ...
*May 31, 2011 by Nick*

**Math**

A man is running around a circular track that is 200m in circumference. An observer uses a stopwatch to record the runner’s time at the end of each lap, obtaining the data in the tale below. a. What was the man’s average speed (rate) between 68 s and 152 s? b. What was the man...
*December 4, 2014 by Kevin*

**physics**

A car travels up a hill at a constant speed of 32 km/h and returns down the hill at a constant speed of 61 km/h. Calculate the average speed and the answer is not 46.5
*September 19, 2011 by Ann2793*

**math**

a motorist goes 78km in 40minutes calculate it speed
*July 4, 2011 by Anonymous*

**physics**

The combined mass of a race car and its driver is 600. kilograms. Traveling at a constant speed, the car completes one lap around a circular track of radius 160 meters in 36 seconds. A) Based on the given information, calculate the speed of the car. B) Calculate the magnitude ...
*January 10, 2010 by Nicole*

**Physics**

I know how to get the speed if it accelerated the whole time. How do I calculate the cruising speed? Starting from rest, a car travels 1,350 meters in 1 min. It accelerated at 1 m/s^2 until it reached its cruising speed. Then it drove the remaining distance at constant ...
*September 7, 2007 by Colin*

**Physics**

A 0.0420-kg hollow racquetball with an initial speed of 18.3 m/s collides with a backboard. It rebounds with a speed of 7.4 m/s. Calculate the total impulse on the ball.
*December 21, 2014 by Brooke*

**Physics- HELP**

How to find average speed with a given initial speed, theta, and delta x? I know average speed= total distance/total time, but I am given an initial speed, an angle and delta x. Mark throws a ball to Daniel with an initial speed of 20 m/s at an angle of 45 degrees. If they are...
*December 1, 2010 by Amm*

**math**

how do you calculate the distance and speed of a motorcycle that is going to jump 4 cars
*August 24, 2011 by linda*

**Physics**

In order to convert a tough split in bowling, it is necessary to strike the pin a glancing blow as shown in Fig. 9-47. The bowling ball, initially traveling at 13.0 m/s, has four times the mass of a pin and the pin flies off at 80° from the original direction of the ball. ...
*March 5, 2014 by Anonymous*

**Physics 4a**

A stone is thrown vertically upward. On its way up it passes point A with speed v, and point B, 7.85 m higher than A, with speed v. Calculate (a) the speed v and (b) the maximum height reached by the stone above point B.
*September 10, 2010 by Antonio*

**physics**

A stone is thrown vertically upward. On its way up it passes point A with speed v, and point B, 7.85 m higher than A, with speed v/2. Calculate (a) the speed v and (b) the maximum height reached by the stone above point B.
*September 10, 2010 by Antonio*

**Physics**

1. A car undergoes a displacement of 500m due east, followed by another displacement due south of 1200m. a)Calculate the total distance traversed by the car d1+d2=total distance 500+1200=1700m b) Calculate the total displacement of the car D=√(500^2+1200^2)=1300 tan^-1(...
*March 1, 2016 by Steve *

**phyics**

A crippled ship is being assisted to port. The motor is stuck, and is moving the boat east with a speed of 15 km/h. The current is flowing a 9 km/h at 30 degrees east of south. A. If the maximum speed of the tugboat which is trying to rescue the disabled ship is 35 km/h, ...
*November 9, 2014 by morgan*

**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's ...
*November 20, 2014 by Anonymous*

**physics - SHM**

Calculate the speed of the pulse from the following: y(x,t) = 2/((x - 3t)^2 + 1) Well the speed of the pulse is given by: y(x,t) = f (x - vt) for a pulse traveling to the right and y(x,t) = f (x + vt) for a pulse traveling to the left but in this case the function is (x - 3t)^...
*April 14, 2007 by COFFEE*

**Chemistry**

Using Heisenberg's Principle, calculate for the following positions. a) a 1.54-mg mosquito moving at a speed of 1.82 m/s if the speed is known to within ± 0.01 m/s b) a proton moving at a speed of (4.67 ± 0.02) 104 m/s When I solved (a) I got 1.88e-30 and (b) I got 3.41e-5 but...
*March 17, 2010 by Anonymous*

**Physics**

Calculate the force needed to bring a 1100–kg car to rest from a speed of 83.0 km/h in a distance of 118 m (a fairly typical distance for a non-panic stop). Suppose instead the car hits a concrete abutment at full speed and is brought to a stop in 1.82 m. Calculate the force ...
*March 16, 2016 by Emiliee*

**plz help physics**

A proton is moving in vacuum along a straight path from A to B .It passes point A at the speed of 2000km/s. a)Calculate in J and in eV the kinetic energy of the proton at A. b)Calculate the value of the positive voltage U that should be applied between A and B so that the ...
*May 3, 2016 by vicky*

**plz help physics!!!!**

A proton is moving in vacuum along a straight path from A to B .It passes point A at the speed of 2000km/s. a)Calculate in J and in eV the kinetic energy of the proton at A. b)Calculate the value of the positive voltage U that should be applied between A and B so that the ...
*May 3, 2016 by vicky*

**physics**

A space habitat for a long space voyage consists of two cabins each connected by a cable to a central hub as shown in the figure below. The cabins are set spinning around the hub axis, which is connected to the rest of the spacecraft to generate artificial gravity. (a) What ...
*November 8, 2010 by Anonymous*

**Physics**

A car of mass 1200kg starts from rest, accelerates uniformly to a speed of 4.0 meters per second in 2.0 seconds and continues moving at this constant speed in a horizontal straight line for an additional 10 seconds. the brakes are then applied and the car is brought to rest in...
*December 4, 2012 by Ken*

**physics**

A 27-kg boy stands 4 m from the center of a frictionless playground merry-go-round, which has a moment of inertia of 238 kg m2. The boy begins to run in a circular path with a speed of 0.6 m/s relative to the ground. (a) Calculate the angular velocity of the merry-go-round. (b...
*March 26, 2011 by Nick*

**physics**

A 27-kg boy stands 4 m from the center of a frictionless playground merry-go-round, which has a moment of inertia of 238 kg m2. The boy begins to run in a circular path with a speed of 0.6 m/s relative to the ground. (a) Calculate the angular velocity of the merry-go-round. (...
*March 26, 2011 by Really stuck in this problem !!*

**physics**

the speed of a bus increase uniform from 15mls 6mls in 20s calculate.a the average speed.b accelaration. c the distance travelled during the either period
*February 8, 2016 by shafiu*

**Physics**

A 23-kg boy stands 3 m from the center of a frictionless playground merry-go-round, which has a moment of inertia of 180 kg m2. The boy begins to run in a circular path with a speed of 0.6 m/s relative to the ground. (a) Calculate the angular velocity of the merry-go-round in ...
*June 18, 2012 by Maria*

**Physics**

Car A and B are passing each other in different lanes. Car A has an initial speed of 15m/s and is gaining speed at 1.5m/s^2. Car B has an initial speed of 20m/s and is gaining speed at 2.0m/s^2. Find when and where the cars will pass one another and their speeds as they are ...
*February 20, 2008 by Anonymous*

**Physics**

A person runs 800. m at an average speed of 6.00 m/s and then the next 800. m at an average speed of 8.00 m/s. Calculate (a) the total time of travel and b) the average speed.
*June 17, 2014 by Jade*

**Physics**

A ball rolls off the edge of a 0.75m high lab table with a horizontal speed of 1.50 m/s. Calculate the time that the ball is in flight, calculate the vertical velocity of the ball just before striking the floor, and calculate the horizontal distance(range) that the ball will ...
*April 16, 2015 by Daniel*

**math- HELP!**

Calculate the linear speed of a bicycle with 26-inch wheels being pedaled at a rate of 200 revolutions per minute. Express your answer in inches per minute rounded to the nearest whole number. (Hint: The diameter of the wheel is 26 inches.) I got: linear speed=r•w r=13 w=200 ...
*January 1, 2016 by Ellie*

**Maths**

A motorist drives at a constant speed of X km/h for 40k and then increases the speed by 20km/h to travel teh next 250km. If the whole journey takes 3 hours,calculate X.
*January 28, 2016 by Nadz*

**Physics**

A child is pushed down a slide from a height of 2.5m with a speed of 7m/s if his mass is 25kg and reaches the ground a speed of 5m/s calculate the coefficient of kinetic friction. Theta = 55 degrees
*April 12, 2016 by Hajju Farouk *

**Physics ( Calculus & Mecahnics ) **

A proton with mass m moves in one dimension.The potential-energy function is where and are positive constants. The proton is released from rest a x0 = a/b. (a) Show that can be written as U(x) = a --- [ ( x0/x )^2 - x0/x ] x0^2 Graph U(x). Calculate U(x0) and thereby locate ...
*January 23, 2011 by Clark*

**physics**

A train travel 20km at a uniform speed 60km/1hr and the next 20km at a uniform speed of 80km/1hr calculate its average speed
*April 1, 2014 by prabhjot*

**Chemistry Help**

The molecules of a certain gas sample at 367 K have a root-mean-square (rms) speed of 261 m/s. Calculate the most probable speed and the mass of a molecule.
*December 5, 2012 by Anonymous*

**Physics**

1. A person runs 800. m at an average speed of 6.00 m/s and then the next 800. m at an average speed of 8.00 m/s. Calculate (a) the total time of travel and (b) the average speed. 2. Sam travels by car from one city to another. He drives for 45.0 min at 95.0 km/h, 30.0 min at ...
*June 24, 2014 by Jade*

**math**

what are the level of speed, speed of sound, speed of light, what are the next levels of speed.
*October 22, 2014 by Lalji*