Tuesday

October 6, 2015
**physics**

velocit of gas molecule is 3m/s at 1000k. at what temperature velocity becomes 12m/s?
*Tuesday, September 15, 2015 by sunny chauhan*

**Physics**

The North American and European continents are moving apart at a rate of about 3.0 cm/yr. At this rate how many years will it take them to drift 500.0 km farther apart than they are present?
*Monday, September 14, 2015 by Haley*

**physics**

A basketball player can jump to a height of 1.1 m off the ground, so he can easily dunk a basketball.For such a leap, what is his "hang time" - the time spent in the air after leaving the ground and before touching down again?
*Monday, September 14, 2015 by Ninie*

**Physics**

A 10.0 kg object is resting on a horizontal surface with a coefficient of friction of 0.7. Determine the minimum force that can move the object.At what inclination should force be applied?
*Monday, September 14, 2015 by May *

**College Physics**

At a firing range, a target is placed 300 m from where someone is firing a rifle. The muzzle speed of this rifle is 700 m/s. If the rifle is aimed directly at the center of the target, by how far will the target miss? At what angle would the rifle need to be aimed at to hit ...
*Monday, September 14, 2015 by Tom*

**Physics**

A model rocket rises with constant acceleration to a height of 3.1 m, at which point its speed is 26.0 m/s. A.) How much time does it take for the rocket to reach this height? B.) What was the magnitude of the rocket's acceleration? C.) Find the height of the rocket 0.15 s...
*Monday, September 14, 2015 by Amanda*

**Physics **

How long does it take an automobile traveling 62.9 km/h to become even with a car that is traveling in another lane at 48.9 km/h if the cars’ front bumpers are initially 130 m apart? Answer in units of s.
*Monday, September 14, 2015 by Brittney*

**physics**

Suppose a soccer player kicks the ball from a distance 28 m toward the goal. Find the initial speed of the ball if it just passes over the goal, 2.4 m above the ground, given the initial direction to be 55° above the horizontal.
*Monday, September 14, 2015 by Anonymous*

**Physics**

"a vector r has a magnitude of 18 units and makes a 30 degree angle with respect to the x axis. find the vector components of r using a protractor and some graph paper to verify your answer by drawing r and measuring the length of the lines representing its components.&...
*Monday, September 14, 2015 by Alyssa*

**Physics**

An 83-kg fireman slides down a fire pole. He holds the pole, which exerts 500-N steady resistive force on the fireman. At the bottom he slows to a stop in 0.49 m by bending his knees. Determine the acceleration of the fireman while sliding down the pole.
*Monday, September 14, 2015 by Iris*

**Physics -Material **

1. If you are designing a product with requirement of a high UTS(Ultimate tensile Strenght), high YS, low ductility steel, what process should you apply onto steel to get the steel with required properties? 2. If you want to get lustrous surface metal, what process should be ...
*Monday, September 14, 2015 by Tina T*

**Physics**

A car starts from rest and accelerate uniformely at 4m/s^2 for 6 seconds. for the next 8 sec. the driver moves with constant velocity. After this the driver applies brakes and stops the car in 10 sec. What is the total distance travelled by the car?
*Monday, September 14, 2015 by Calvin*

**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
*Monday, September 14, 2015 by Jay*

**Physics **

A student rides his skateboard for 10 minutes and travels 1.2 miles. What is the average speed of the skateboarder in miles/minute?
*Monday, September 14, 2015 by Tesha*

**Physics **

A boat traveling at 9.50 m/s relative to the water aims to go straight across a river. If the river is 106.0 m wide and the current in the river is 3.50 m/s, how far downstream will the boat land on the other side of the river? Calculate the answer in meters (m) and rounded to...
*Monday, September 14, 2015 by Anonymous*

**Physics**

If six points charges are distributed on a balloon encased within a cube,in such a manner that the points charges appear like dots on a die and if each point charge has a value of -q for its charge, and the radius of the balloon is R, what is the magnitude of the NET Electric ...
*Sunday, September 13, 2015 by Deirdra*

**Physics**

If each point charge has a value of -q for its charge, and the radius of the balloon is R, what is the magnitude of the NET Electric Field, E, at the location of each point charges, due to the other five? Your answer may only be in terms of q, R, π, k, and ε0
*Sunday, September 13, 2015 by Deirdra*

**Physics**

Ball A is kicked at 40° above the horizontal. Ball B is kicked with the same horizontal component of velocity but at 55°. The speed of A is ( >or< ) the speed of B. The time A is in the air is ( >or< ) the time B is in the air. The range of A is ( >or&...
*Sunday, September 13, 2015 by Blake*

**physics**

Vector Upper A Overscript right-arrow EndScripts has a magnitude of 75 units and points due west, while vector Upper B Overscript right-arrow EndScripts has the same magnitude and points due south. Find the magnitude and direction of (a) Upper A Overscript right-arrow ...
*Sunday, September 13, 2015 by Jess*

**Science (Physics)**

(3.2534x10^4m)+(7.25x10^6m)/(4.26442x10^-3km)-(7.1299x10^-5km)
*Sunday, September 13, 2015 by Marisa*

**Physics 111**

A boat is crossing a river. The velocity of the boat relative to the water is 4.0 m/s directed perpendicular to the river's current. The velocity of the current relative to the shore is 2.0 m/s. How long will it take for the boat to cross the river?
*Sunday, September 13, 2015 by Hannah*

**Physics**

An ice sled powered by a rocket engine starts from rest on a large frozen lake and accelerates at +15.0 m/s2. At tl = 2.8 s the rocket engine is shut down and the sled moves with constant velocity v. At the 7800 m mark, the sled begins to accelerate at -7 m/s2. What is the ...
*Sunday, September 13, 2015 by Ab*

**physics**

A person travels by car from one city to another. She drives for 21.8 min at 67.1 km/h, 13.1 min at 84.6 km/h, 51.4 min at 33.5 km/h, and spends 11.5 min along the way eating lunch and buying gas. Determine the distance between the cities along this route.
*Sunday, September 13, 2015 by Anonymous*

**physics**

What was the angle at which the car left the road if it hit a house at the apex of its flight and traveled 50 feet horizontally and 20 feet vertically?
*Sunday, September 13, 2015 by Lyndsey*

**Physics**

You are asked to consult for the city's research hospital, where a group of doctors is investigating the bombardment of cancer tumors with high-energy ions. The ions are fired directly toward the center of the tumor at speeds of 5.6 ×106m/s. To cover the entire tumor...
*Sunday, September 13, 2015 by Danielle*

**Physics**

A hockey player is standing on his skates on a frozen pond when an opposing player, moving with a uniform speed of 2.0 m/s, skates by with the puck. After 1.00 s, the first player makes up his mind to chase his opponent. If he accelerates uniformly at 0.20 m/s2, determine each...
*Sunday, September 13, 2015 by Tina*

**Physics**

A certain aircraft has a liftoff speed of 126 km/h. (a) What minimum constant acceleration does the aircraft require if it is to be airborne after a takeoff run of 244 m? m/s2 (b) How long does it take the aircraft to become airborne? s
*Sunday, September 13, 2015 by Vitinna*

**Physics**

You throw a ball with a mass of 160 g into the air with an initial speed of 19.8 m/s. How high does the ball rise?
*Sunday, September 13, 2015 by Nicole*

**Physics**

A brick is dropped out of a window. It hits the ground 3.64 seconds later. How high is the window?
*Sunday, September 13, 2015 by Nicole*

**physics**

One afternoon, a couple walks three-fourths of the way around a circular lake, the radius of which is 2.12 km. They start at the west side of the lake and head due south to begin with. (a) What is the distance they travel? (b) What is the magnitude of the couple’s ...
*Sunday, September 13, 2015 by Jess*

**physics**

A tennis player serves a tennis ball it is moving horizontally when it leaves the racquet. When the ball travels a horizontal distance of 12 meters, it has dropped 55cm from its original height when it left the racquet. What is the initial speed of the ball? (neglect air ...
*Sunday, September 13, 2015 by jack*

**Physics**

A rocket accelerates from rest at 17 m/s2 for 11 s. How far will it cover during this time? Answer in units of m. How do I solve this? do I multiply 17m/s2 by 11 seconds??
*Sunday, September 13, 2015 by Adal*

**physics**

The data in the following table describe the initial and final positions of a moving car. The elapsed time for each of the three pairs of positions listed in the table is 0.52 s. Review the concept of average velocity in Section 2.2 and then determine the average velocity (...
*Sunday, September 13, 2015 by Jess*

**college physics**

You step onto a hot beach with your bare feet. A nerve impulse, generated in your foot, travels through your nervous system at an average speed of 124 m/s. How much time does it take for the impulse, which travels a distance of 1.60 m, to reach your brain?
*Sunday, September 13, 2015 by jess*

**physics**

A tennis player serves a tennis ball it is moving horizontally when it leaves the racquet. When the ball travels a horizontal distance of 12 meters, it has dropped 55cm from its original height when it left the racquet. What is the initial speed of the ball?
*Sunday, September 13, 2015 by jack*

**Physics**

If a ball is thrown at an initial speed of 8.0m/s at an angle of 35 degrees above the ground, what is the speed of the ball when it returns to its original height?
*Sunday, September 13, 2015 by Jacob*

**Physics**

A 0.0500 kg ice cube at -30.0◦C is placed in 0.400 kg of 35.0◦C water in a very well insulated container. What is the final temperature? (Note: how can you check if all the ice melts at equilibrium temperature?)
*Sunday, September 13, 2015 by Anonymous*

**Physics**

A 0.0500 kg ice cube at -30.0◦C is placed in 0.400 kg of 35.0◦C water in a very well insulated container. What is the final temperature? (Note: how can you check if all the ice melts at equilibrium temperature?)
*Sunday, September 13, 2015 by Anonymous*

**physics**

a ball tossed up at a rate of 8.7 ms/ and catches the ball at the same place on the way down. How long was the ball in the air?
*Sunday, September 13, 2015 by connor*

**Physics **

6) A school bus moves at 2.2 m/s as it pulls away from the bus stop what is the speed of the bus 20 s later after its speed has increased by 5.225 m/s? 7) The height of a computer screen is 31.25 cm and its width is 47 cm. a) is the area of the screen known to one, two, three...
*Sunday, September 13, 2015 by anonymous *

**Physics**

On the question that someone posted.....I asked my teacher on what formula I should use and said I should use this one: V^2= Vo^2+2ax (V^2 is the velocit, Vo is the initial velocity, a is accerlation and x distance . An automobile is traveling at 30 km/hr. It accelerates at 3...
*Sunday, September 13, 2015 by Rose*

**Physics **

how are the fundamental laws and principles of physics related to the complexity that we see in nature? 2) How do the laws of physics apply to other sciences such ad biology, chemistry, and earth science? Give a specific example to show the connection - is it because there ...
*Sunday, September 13, 2015 by anonymous *

**Physics**

The driver pushes the accelerator pedal as far down as possible. The car does not accelerate above a certain maximum speed. Explain the reason for this in terms of the forces acting on the car.
*Sunday, September 13, 2015 by Peter*

**Physics**

A 2500-kg car is traveling at 20 m/s around a road curve of radius 200 m. Find the central force acting on the car?
*Sunday, September 13, 2015 by Jen*

**Physics **

A metal ball tied to the end of a string 1.8 m long is whirled in a horizontal circle at 4 m/s. What is the mass of the ball if the tension on the string is 30 N? What formula/s should I use?
*Sunday, September 13, 2015 by Fey*

**Physics**

The gravitational force between two masses is 500N. What is the gravitational force if the masses are doubled and distance between them is likewise doubled? What formula/s should I use?
*Sunday, September 13, 2015 by Hannah *

**PHYSICS**

the gravitational force between two masses is 500 N. What is the gravitational force if the masses are doubled and distance between them is likewise doubled?
*Sunday, September 13, 2015 by NotYourTyn*

**PHYSICS**

An object weighs 480 N on earth. What would its weight be on a planet whose mass is twice the mass and ratio of the earth?
*Sunday, September 13, 2015 by NotYourTyn*

**PHYSICS **

A metal ball tied to the end of a string 1.8 m long is whirled in a horizontal circle at 4 m/s. What is the mass of the ball if the tension on the string is 30 N?
*Sunday, September 13, 2015 by NotYourTyn*

**PHYSICS**

A car with a uniform speed of 60km/h enters a circular flat curve whose radius is .50 km. If the friction between the road and the car's tires can supply a central accekeration of 1.25 m/s^2, dies the car negotiate the curve safely? Prove your answer.
*Saturday, September 12, 2015 by NotYourTyn*

**Physics**

A 4000 kg trailer is towed up a hill with a 5% grade. If the towing truck starts from rest at the bottom of the hill and reaches a speed of 12 m/s at the top of the hill, how much is the towing force. The road from the bottom to the top of the hill is straight with a length of...
*Saturday, September 12, 2015 by Anonymous*

**Physics**

Explain how the electric potential energy of a particle can increase when moving from a region of high electric potential to a region of low electric potential energy.
*Saturday, September 12, 2015 by Kelsey*

**Physics**

Ball A is thrown upward from the top of a building and takes 12 s to hit the ground. Ball B is thrown downward with the same speed as Ball A and takes 7 s to hit the ground. How long does it take for ball A to reach it peak?
*Saturday, September 12, 2015 by Kendra*

**physics relativistic energy**

I'm not too good with these special relativity problems :/ The question is: A 20 kiloton bomb releases 8 x 10^13 joules. How much mass must be converted into other forms of energy? You are already given Energy, would I still use the E=mc^2 formula?? E=(2.0*10^7 kg)(3*10^8 ...
*Saturday, September 12, 2015 by paul*

**Physics**

Find the change of the mechanical energy of a 1000-kg car traveled down an incline with 1:10 grade a total distance of 100 m during which its speed increased from 10 m/s to 20 m/s? Is my answer correct, if not what did I do wrong? ME=KE+PE+Q KE=[.5*1000*20^2]- [.5*1000*10^2] ...
*Saturday, September 12, 2015 by Is my answer correct?*

**physics**

A stone is dropped from the top of a tower 400 m high and at the same time another stone is projected upward vertically from the ground with a velocity of 100 ms −1 . Find where and when the two stones will meet.
*Saturday, September 12, 2015 by Deepa*

**Physics**

A person exerts a force of 90 N on a rope that pulls a sled across a very smooth surface. The rope is oriented 37∘ above the horizontal. The sled has a total mass of 40 kg . The sled starts at rest and moves for 10 m.
*Saturday, September 12, 2015 by Alex*

**PHYSICS**

the gravitational forve between two masses is 500 N. What is the gravitational force if the masses are doubled and distance between them is likewise doubled?
*Saturday, September 12, 2015 by Princess Blabla*

**PHYSICS**

An object weighs 480 N on earth. what would its weight be on a planet whose mass is twice the mass and half the ratio of the earth?
*Saturday, September 12, 2015 by Princess Blabla*

**PHYSICS**

a metal ball tied to the end of a string 1.8 m long is whirled in a horizontal circle at 4 m/s. what is the mass of the ball if the tension on the string is 30 N ?
*Saturday, September 12, 2015 by Princess Blabla*

**PHYSICS**

A wheel of radius 1.5 m rotates at a uniform speed. If a point on the rim of the wheel has a central acceleration of 1.5 m/s ^2. what is the point's tangential speed?
*Saturday, September 12, 2015 by Princess Blabla*

**PHYSICS**

a 2500-kg car is travelling at 20 m/s around a road curve of radius 200 m. Find the central force acting on the car?
*Saturday, September 12, 2015 by Princess Blabla*

**PHYSICS**

two equal masses of 12kg each are 2m apart. WHat is the gravitational force between them?
*Saturday, September 12, 2015 by Princess Blabla*

**Physics**

A car is at mile marker 132 on the highway heading North. Of the car is traveling with a velocity of 24 mi/hr, what mile marker will the car be at after 150 minutes
*Saturday, September 12, 2015 by Michael*

**Physics**

A rescue helicopter drops a package of emergency ration to a stranded party on the ground. If the helicopter is travelling horizontally at 40m/s at a height of 100m above the ground, what are the horizontal and vertical component of the velocity of the package just before it ...
*Saturday, September 12, 2015 by Ramla*

**physics**

A 4000 kg trailer is towed up a hill with a 5% grade. If the towing truck starts from rest at the bottom of the hill and reaches a speed of 12 m/s at the top of the hill, how much is the towing force. The road from the bottom to the top of the hill is straight with a length of...
*Friday, September 11, 2015 by james*

**Physics**

Two soccer players, Mary and Jane, begin running from nearly the same point at the same time. Mary runs in an easterly direction at 3.61 m/s, while Jane takes off in a direction 63.3o north of east at 5.44 m/s. How long is it before they are 23.6 m apart?How far apart are they...
*Friday, September 11, 2015 by Martina*

**physics**

When a car moves up an incline, does the kinetic energy and potential energy decrease or increase?
*Friday, September 11, 2015 by Sandy *

**Physics-Trajectory **

A particle's trajectory is described by x =(12t3−2t2)m and y =(12t2−2t)m, where t is in s. What is the particle's speed at t=0s ? What is the particle's speed at t=5.0s ? Express your answer using two significant figures. What is the particle's ...
*Friday, September 11, 2015 by Eric *

**Physics **

Three forces are exerted on an object placed on a tilted floor. Forces are vectors. The three forces are directed as shown in the figure. If the forces have magnitudes F1 = 2.0 N, F2 = 17.0 N and F3 = 15.0 N, where N is the standard unit of force, what is the component of the ...
*Friday, September 11, 2015 by Eric *

**Physics**

The components of vector A⃗ are Ax = + 3.90 and Ay = -4.00. What is the angle measured counterclockwise from the +x-axis to vector A⃗ ?
*Friday, September 11, 2015 by Eric *

**Physics-VECTORS**

Find the vector's magnitude and direction. Part A A⃗ = 4 i^− 8 j^ A =? θA =?
*Friday, September 11, 2015 by Eric *

**Physics **

A rocket-powered hockey puck moves on a horizontal frictionless table. The figure below shows the graphs of vx and vy, the x- and y-components of the puck’s velocity. The puck starts at the origin. The graph of the X-velocity is v=8t cm/s and the Y-velocity is V=30cm/s ...
*Friday, September 11, 2015 by Eric *

**Physics**

A very narrow beam of white light is incident at 56.10° onto the top surface of a rectangular block of flint glass 12.7 cm thick. The indices of refraction of the glass for red and violet light are 1.640 and 1.663, respectively. Calculate the dispersion angle (i.e., the ...
*Friday, September 11, 2015 by Rachel*

**Physics**

An object is placed 11.3 cm to the left of a diverging lens of focal length -6.51 cm. A converging lens of focal length 11.6 cm is placed a distance of d to the right of the diverging lens. Find the distance d that places the final image at infinity.
*Friday, September 11, 2015 by Rachel*

**physics**

Two planes are initially separated by a horizontal distance of 350 km. Plane A is positioned 350 km west of the Plane B. Plane A is initially traveling at a velocity of 60 m/s east. Plane B is traveling at a velocity of 45 m/s west. If plane A begins to accelerate east at a ...
*Friday, September 11, 2015 by Vj*

**physics**

One cubic centimetre (1.0 cm3) of water has a mass of 1.0 × 10−3 kg. (a) Determine the mass of 1.0 litre of water. Assuming that biological substances are 98% water, estimate the masses of (b) a cell with a diameter of 1.0 μm, (c) a human kidney, and (d) a fly...
*Friday, September 11, 2015 by Jas*

**Physics**

Two passenger trains are passing each other on adjacent tracks. Train A is moving east with a speed of 35.5 m/s, and train B is traveling west with a speed of 33.4 m/s. (a) What is the velocity (taking due east to be the positive direction) of train A as seen by the passengers...
*Friday, September 11, 2015 by JJ*

**physics**

You are traveling in a convertible with the top down. The car is moving at a constant velocity of 17.5 m/s, due east along flat ground. You throw a tomato straight upward at a speed of 13.0 m/s. How far has the car moved when you get a chance to catch the tomato?
*Friday, September 11, 2015 by ar*

**physics**

A rocket is fired at a speed of 66.0 m/s from ground level, at an angle of 63.0 ° above the horizontal. The rocket is fired toward an 31.2-m high wall, which is located 28.0 m away. The rocket attains its launch speed in a negligibly short period of time, after which its ...
*Friday, September 11, 2015 by amanda*

**physics**

A swimmer, capable of swimming at a speed of 1.18 m/s in still water (i.e., the swimmer can swim with a speed of 1.18 m/s relative to the water), starts to swim directly across a 2.16-km-wide river. However, the current is 1.19 m/s, and it carries the swimmer downstream. (a) ...
*Friday, September 11, 2015 by amanda*

**physics**

A mountaintop is a height y above the level ground. A woman measures the angle of elevation of the mountaintop to be θ when she is a horizontal distance x from the mountaintop. After walking a distance d closer to the mountain, she measures the angle of elevation of the ...
*Friday, September 11, 2015 by jasleen*

**Physics**

A pilot flying low and slow drops a weight; it takes 2.8 s to hit the ground, during which it travels a horizontal distance of 100 m . Now the pilot does a run at the same height but twice the speed. How much time does it take the weight to hit the ground? How far does it ...
*Friday, September 11, 2015 by Lina*

**Physics**

An object travels with a constant acceleration for 10 s. The vectors in Figure 3-41 represent the final and initial velocities. carefully graph the x component of the velocity versus time, the y component of the velocity versus time and the y component of the acceleration ...
*Friday, September 11, 2015 by Alyssa*

**Physics. Help Please**

Gabriele enters an east-w straight bike path at the 3.0-km mark and rides w at a constant speed of 8.0 m/s. At the same time, Xena rides east from the1.0-km mark at a constant speed of 6.0 m/s. 1. Write function x(t) that describe the position of Gabriele as a function of time...
*Friday, September 11, 2015 by Matt*

**Physics**

An object travels with a constant acceleration for 10 s. The vectors in Figure 3-41 represent the final and initial velocities. carefully graph the x component of the velocity versus time and the y component of the acceleration versus time, in a Vx vs t graph, a Vy vs t graph ...
*Friday, September 11, 2015 by Alyssa*

**physics**

a man can swim in still water At 5 km/h . in order to cross the river through shortest path , at what approximate angle he should swim at, with the upstrem ?
*Friday, September 11, 2015 by Akansha*

**physics **

Two springs have force constant K1&K2 (K1>K2) .each spring is extended by same farce F. If their elastic potential energy are E1&E2then E1/E2)is?
*Friday, September 11, 2015 by Bn sharma*

**Physics **

During an all-night cram session, a student heats up a 0.360 liter (0.360 x 10- 3 m3) glass (Pyrex) beaker of cold coffee. Initially, the temperature is 18.1 °C, and the beaker is filled to the brim. A short time later when the student returns, the temperature has risen to...
*Friday, September 11, 2015 by can anyone help me with this *

**Physics**

A treasure map instructs you to walk 27 m south, followed by 70 m east, then 64.5 m north, and finally 28.5 m east. Determine the magnitude of your total displacement, if you follow these instructions. Calculate the answer in meters (m) and rounded to three significant figures.
*Friday, September 11, 2015 by Anonymous*

**Physics**

To qualify for the finals in a racing event a car must achieve an average speed of 250 km/h on a track with a total length of 16,000 m if a particular car covers the first half of the track at an average speed of 230 km/h what minimum average speed Must It have in the second ...
*Thursday, September 10, 2015 by Aleksa*

**Physics**

A speed skater moving across frictionless ice at 8.3 m/s hits a 5.6 m -wide patch of rough ice. She slows steadily, then continues on at 6.5 m/s What is he acceleration on the rough ice?
*Thursday, September 10, 2015 by Caylee*

**Physics**

Calculate the total entropy change hat occurs when 2kg of lead at 40 degrees celcius are placed in a very large quantity of water at 10degrees celcius. the specific heat of lead is 0.031 cal/g K).
*Thursday, September 10, 2015 by Kelsey*

**physics- work **

what is the work required to raise a 10-kg bucket from a well 100-meter deep? Is this right? 10*9.8= 98N 98N*100= 9800J
*Thursday, September 10, 2015 by Anonymous*

**physics**

Which of the following does not involve a force? a.tug of war b.pushing a wagon c.riding a bike d.jumping e.None of the above f.towing a car g.hitting a ball Is the answer e. none of the above? I know a,b,c,d, and g exert a force, but I am not sure about f. towing a car.
*Thursday, September 10, 2015 by Anonymous*

**Physics Using hydrostatic equilbrium)**

3. A model of Earth’s interior: Look up the radius and mass of the Earth. Radius is 6,371 km Mass is 5.974 x 10^24 kg Calculate its average density. p_e = (5.974 x 10^24 kg)/ (4/3)pi r^3 = (5.974 x 10^24 kg)/ (4/3)pi (6371)^3 = 5.54 g/cm^3 Using this Imagine a planet of ...
*Thursday, September 10, 2015 by Jason*

**physics **

A ball is dropped from a helicopter which is descending at 1.5 m/s. After 2 seconds, what are a) the the velocity of the ball, and b) how far is the ball below the helicopter? c) & d) Repeat your calculations for a) and b) if the helicopter had been rising at 1.5 m/s instead.
*Thursday, September 10, 2015 by john smith*

**Physics**

The Space Shuttle travels at a speed of about 5.05 x 103 m/s. The blink of an astronaut's eye lasts about 93.5 ms. How many football fields (length = 91.4 m) does the Space Shuttle cover in the blink of an eye?
*Thursday, September 10, 2015 by Garren*

**Physics**

t a NASA research center free-fall research is performed by dropping experiment packages from the top of an evacuated shaft 156 m high. Free-fall imitates the so-called microgravity environment of a satellite in orbit. What constant acceleration would be required to stop an ...
*Thursday, September 10, 2015 by Ali*

**Physics (deriving Keplers 3rd law)**

How do I derive a straightforward form of Kepler's 3rd Law if I start with Newtons's Law of Gravitation. (the opposite of what Newton did)
*Thursday, September 10, 2015 by Jason*