Saturday

April 19, 2014

April 19, 2014

Number of results: 79

**Phyiscs**

N=m*v/t
*Wednesday, November 25, 2009 at 12:21am by Dixie*

**phyiscs**

1.5*10power13
*Friday, October 29, 2010 at 8:35am by Anjali*

**phyiscs**

Yes.
*Thursday, April 4, 2013 at 6:13pm by Abraham Lincoln*

**Phyiscs**

nuclear disintegration. Radioactivity.
*Sunday, November 29, 2009 at 2:34pm by bobpursley*

**phyiscs**

In a nuclear power plant, _
*Thursday, April 4, 2013 at 6:13pm by Anonymous*

**ap phyiscs**

I will be glad to critique your work
*Sunday, February 10, 2008 at 8:57pm by drwls*

**Phyiscs help 3**

These are incredibly simple to work. What is your difficulty?
*Sunday, November 9, 2008 at 11:46pm by bobpursley*

**phyiscs**

t=(v-Vo)/a = (25-10)/(0.5*9.8) =3.06 s.
*Tuesday, October 15, 2013 at 8:02am by Henry *

**phyiscs**

The drawing would help understand where the left support is.
*Friday, November 19, 2010 at 4:02pm by bobpursley*

**simple PHYISCS**

h=gt²/2 t=sqrt(2•5/g)=1.01 s
*Tuesday, April 2, 2013 at 4:08am by Elena*

**1 more phyiscs for today**

thank you tahnk you. it makes sense now
*Thursday, November 6, 2008 at 7:03pm by joyce*

**Phyiscs**

I bet summing moments around any point will solve this.
*Wednesday, April 27, 2011 at 1:28pm by bobpursley*

**Phyiscs**

two examples of everyday devices of relativity? besides a gps?
*Sunday, November 29, 2009 at 2:34pm by Jordan*

**phyiscs **

the density of mercury is 13.6gm .Find the volume of 0.3 of hg
*Tuesday, November 13, 2012 at 2:09pm by safel mma*

**phyiscs**

i feel like slapping myself across the face... i completely forgot about gravity...
*Tuesday, January 15, 2013 at 5:33pm by v*

**Phyiscs**

Vo is zero, starting at the top. T= sqrt(2x/g) where g is the component of gravity down the plane 9.8sin22
*Saturday, July 11, 2009 at 7:39pm by bobpursley*

**phyiscs repost 2**

2.25 microwatts is a millionth of a watt, or 2.25x10^-6 W/m^2. This is divided by 1e-12, so the solution is: B=10log10(2.25e+6)
*Saturday, April 19, 2008 at 8:14pm by Anonymous*

**AP PHYISCS**

Force * (Stopping distance) = work done on the snow = kinetic energy at impact = (1/2) M V^2 X = (1/2) M V^2/(1.2 x 10^8 N) The impulse, I, is equal to the momentum change I = M V
*Saturday, January 12, 2008 at 10:23pm by drwls*

**1 more phyiscs for today**

force(distancestopped)=mgh force(.75)=massball*g*heighthelo
*Thursday, November 6, 2008 at 7:03pm by bobpursley*

**Phyiscs**

The child is going from a speed of 112 mi/h to a speed of 0 in .12 seconds...so their is a deceleration...Does this help?
*Wednesday, November 25, 2009 at 12:21am by DanH*

**Phyiscs**

A 40,000 kg jet has a force of 3.9×10^3 newtons. what is the acceleration of the jet
*Wednesday, April 3, 2013 at 10:28pm by Nate*

**phyiscs **

A car has an acceleration of 0.5g. calculate the time for the car to accelerate from 10m/s to 25m/s
*Tuesday, October 15, 2013 at 8:02am by abdul*

**phyiscs**

if 0.4 force is required to pull a body attaching to spring 0.1m from the position of equality find the spring constant?
*Friday, October 29, 2010 at 7:06am by madiha*

**phyiscs**

if 0.4 force is required to pull a body attaching to spring 0.1m from the position of equality find the spring constant?
*Friday, October 29, 2010 at 7:08am by madiha*

**PHyiscs**

A HELICOPTER hovering above a forest fire dumps a large bucket of water. How far does the water fall in the first 3.0 seconds t=3.0s
*Friday, September 24, 2010 at 4:05pm by ANON*

**phyiscs**

Using standard equation the height is given by: s=uT+0.5aT^2 if it is dropped u=0 s=0.5aT^2 2.90 t^3 = 0.5 9.8 T^2 substitute value for t as 1.75 s and find T
*Monday, September 19, 2011 at 7:09am by Dr Russ*

**college phyiscs**

A car starts from rest on a curve with a radius of 160 m and accelerates at 1.80 m/s^2. How many revolutions will the car have gone through when the magnitude of its total acceleration is 2.20 m/s^2?
*Sunday, October 11, 2009 at 11:57am by Amanda*

**phyiscs help please**

work done by friction? forcefriction*distance mu*(mg-3E2sin18)*distance check my thinking. Remember, the rope is pulling upward, so it reduces the normal force of weight.
*Friday, October 29, 2010 at 10:37am by bobpursley*

**college phyiscs**

the angular acceleration is 1.60/160 in radian/s^2 I dont see how anything can be solved without know how long it accelerated at this acceleration. Displacement is a function of time, and acceleration.
*Sunday, October 11, 2009 at 11:57am by bobpursley*

**phyiscs**

Typo in first sentece: I meant to say: The important point is that an antenna that is much shorter than the wavelength will have a radiation resistance that will be far less than the internal ohmic resistance.
*Friday, May 29, 2009 at 1:02pm by Count Iblis*

**PHyiscs**

Use: Distance S = ut+(1/2)gt² u=initial velocity =0 m/s g=acceleration due to gravaity=-9.8 m/s² t=time in seconds. S=vertical distance in metres.
*Friday, September 24, 2010 at 4:05pm by MathMate*

**phyiscs**

What is the spring constant of a spring that stretches 2.00 cm when a mass of 0.600 kg is suspended from it? Answer i know the answer is 295 n/m but im nto sure how they got to it,
*Tuesday, January 15, 2013 at 5:33pm by v*

**phyiscs**

Many kayaks are made of plastics and other composite materials that are denser than water. How are such kayaks able to float in water? Does the kayak displace water? What exactly is Archimedes's Principle?
*Tuesday, May 8, 2007 at 9:43pm by Anonymous*

**phyiscs**

Why is an antenna designed to be one-half of the wavelength of the wave it is supposed to receive? In my book all it says is that the voltage is larger when the antenna is 1/2 the wavelength of the wave.
*Friday, May 29, 2009 at 1:02pm by sally*

**Phyiscs**

find time to fall. h=1/2 g t^2 find time. g=32ft/sec^2 Now, the train: d=rt 50ft=v*t v will be in ft/sec
*Monday, September 5, 2011 at 9:42am by bobpursley*

**Phyiscs**

A rock is tossed straight up with a velocity of 33.9 m/s. When it returns, it falls into a hole 11.9 m deep. What is the rock's velocity as it hits the bottom of the hole?
*Monday, October 4, 2010 at 8:24pm by Em*

**phyiscs**

The height of a helicopter above the ground is given by h = 2.90t3, where h is in meters and t is in seconds. At t = 1.75 s, the helicopter releases a small mailbag. How long after its release does the mailbag reach the ground?
*Monday, September 19, 2011 at 7:09am by fayez*

**Phyiscs**

A hollow copper tube (diameter = 4.01 cm) is sealed at one end and loaded with lead shot to give a total mass of 0.218 kg. When the tube is floated in pure water, what is the depth, z, of its bottom end?
*Thursday, April 3, 2014 at 5:17pm by Jason*

**phyiscs repost 2**

Calculate the sound level in decibels of a sound wave that has an intensity of 2.25 µW/m2 For this question don't I use B=log10(I/IO) So it would be B=log10(2.25/1.0e-12) right?
*Saturday, April 19, 2008 at 8:14pm by chris adison*

**Phyiscs**

A man claims he can safely hold on to a 9.7-kg child in a head-on collision with a relative speed of 112-mi/h lasting for 0.12 s as long as he has his seat belt on. (a) Find the magnitude of the average force needed to hold onto the child. HELP
*Wednesday, November 25, 2009 at 12:21am by Rick*

**phyiscs**

A stone is thrown horizontaly from the top of a 25.00-m cliff. The stone lands at a distance of 40.00 m from the edge of the cliff. What is the horizontal velocity of the stone?
*Friday, October 22, 2010 at 11:23am by ashlee*

**Phyiscs**

d = Vo*t + 0.5gt^2 = 36 ft. 0 + 0.5*32t^2 = 36, 16t^2 = 36, t^2 = 2.25, t = 1.5s. d = Vt, V = d / t = 50 / 1.5 = 33.33 Ft / s.
*Monday, September 5, 2011 at 9:42am by Henry*

**phyiscs**

A uniform plank of length 4.5 m and weight 233 N rests horizontally on two supports, with 1.1 m of the plank hanging over the right support (see the drawing). To what distance x can a person who weighs 454 N walk on the overhanging part of the plank before it just begins to tip?
*Friday, November 19, 2010 at 4:02pm by jason*

**Phyiscs **

A 5.00g lead bullet is fired into a wooden fence post. The initial speed of the bullet is 250m/s, and when it comes to rest, half its kinetic energy goes into heating bullet. How much does the bullet's temperature increase?
*Sunday, November 25, 2012 at 5:20pm by noname*

**phyiscs**

A bolt is dropped from a bridge under construction, falling 81 m to the valley below the bridge. (a) How much time does it take to pass through the last 28 % of its fall? What is its speed (b) when it begins that last 28 % of its fall and (c) just before it reaches the ground?
*Thursday, September 12, 2013 at 4:07pm by kristy*

**phyiscs**

what is the derivative of velocity squared? i know that the derivative of regular velocity is acceleration, but what about velocity squared? thank you very much!
*Thursday, May 19, 2011 at 2:14pm by physics*

**phyiscs**

Two persons watch the same object move john says that it accelerate straight downward, but Samantha claims that it falls Along curved path.describe the conditions under which each person would be reporting correctly what they see. Thanks and please please please answer this ...
*Friday, April 1, 2011 at 2:45pm by tim*

**Phyiscs**

A satellite circles the earth in an orbit whose radius is 2.07 times the earth's radius. The earth's mass is 5.98 x 1024 kg, and its radius is 6.38 x 106 m. What is the period of the satellite?
*Sunday, June 30, 2013 at 8:50pm by Justin S.*

**Phyiscs**

112 m/h = 180 km/h = 50 m/s The deceleration rate is a = (50 m/s)/0.12s = 416 m/s^2 That's about 42 g's. The force to hold the child required is F = m a, which is about 42 times the child's weight. Do the calculation and answer in Newtons or pounds..
*Wednesday, November 25, 2009 at 12:21am by drwls*

**Phyiscs**

True or false: When a system consists of several objects, each with their own mass and velocity, the linear momentum of the system as a whole is simply the product of the system's total mass and the velocity of the system's center of mass.
*Tuesday, October 30, 2012 at 1:40pm by Angelena*

**Phyiscs**

A woman is standing on the middle of a ladder that leans up against a building, with an angle of 65 degrees from the ground. The wall is very slippery and the ladder is very light. What is the minimum coefficient of friction needed between the ground and the ladder so that the...
*Wednesday, April 27, 2011 at 1:28pm by Anonymous*

**phyiscs- rube goldberg machine**

Identify two types of simple machines that are included in a Rube Goldberg machine. Pick any simple machines: For example, wedge, and lever.
*Saturday, January 13, 2007 at 4:52pm by Anonymous*

**Phyiscs**

The heat capacity of lead is C = .127.10^3J/kg*K (I googled it) So the heat capacity of the bullet is Cm=.635 J/K The kinetic energy of your bullet is KE = 1/2*5.10^-3 250^2 J Therefore the increase in temp will be 1/2KE/(Cm) = 123 degrees
*Sunday, November 25, 2012 at 5:20pm by Sonja*

**1 more phyiscs for today**

sorry for asking for help agen. a baseball catcher puts on an exhibition by catching a .150kg ball dropped from a helicopter at a height of 100m above the catcher. if the catcher "gives with the ball for a distance of .75m while catching it, what average force is exerted on ...
*Thursday, November 6, 2008 at 7:03pm by joyce*

**phyiscs!**

Having landed on a newly discovered planet, an astronaut sets up a simple pendulum of length 1.51 m and finds that it makes 291 complete oscillations in 697 s. The amplitude of the oscillations is very small compared to the pendulum’s length. What is the gravitational ...
*Wednesday, November 16, 2011 at 11:50pm by amanda*

**Physics**

Sense I'm not taking Physics C but Physics B I guess I'm not expected to find the value of the drag force sense that would involve soem calculus. I just have a question though. If we performed a lab outside wouldn't the drag force vary from time to time sense the wind could ...
*Sunday, August 9, 2009 at 4:44pm by Phyiscs*

**simple PHYISCS**

A teenager accidentally falls off a 10 m high platform diving board. His friend whips out his camera and takes a picture when the teenager is halfway to the water below to commemorate the embarrassing event and post it on Facebook. How many seconds after the teenager fell off ...
*Tuesday, April 2, 2013 at 4:08am by Anyone....out...help..please!!!*

**Phyiscs help 3**

The height of a tower is measured by attaching a simple pendulum to its ceiling, whose length is barely enough to stay off the floor. The pendulum is let go from a small angle, and takes 13 s to return to the same location it started from. a.) How tall is the tower? ? m If the...
*Sunday, November 9, 2008 at 11:46pm by kelsey*

**Phyiscs**

A stone falls from a railroad overpass which is 36 ft high into the path of a train which is approaching the overpass with a uniform speed. If the stone falls when the train is 50 ft away from the overpass and the stone hits the ground just as the train arrives at that spot, ...
*Monday, September 5, 2011 at 9:42am by Stone*

**AP PHYISCS**

A paratrooper fell 380m from an airplane without being able to open his chute but happened to land in snow, suffering only minor injuries. Assume that his speed at impact was 58 m/s(terminal speed), that his mass (including gear) was 90 kg, and that the force on him from teh ...
*Saturday, January 12, 2008 at 10:23pm by Kristen*

**Phyiscs - Electro static**

Particles 1 and 2 of charge q1 = q2 = +3.20 x 10-19 C are on a y axis at distance d = 22.0 cm from the origin. Particle 3 of charge q3 = +9.60 x 10-19 C is moved gradually along the x axis from x = 0 to x = +5.0 m. At what value of x will the magnitude of the electrostatic ...
*Saturday, April 2, 2011 at 2:05pm by will*

**Phyiscs**

A lbock is given an intial speed of 4.0 s^-1 m up the 22 degree plane How far up the plane will it go ok I got this to be something like 2.2 about i understand this i need help on this how much time elapses before it returns to tis starting point? Ignore friction. ok I need to...
*Saturday, July 11, 2009 at 7:39pm by Physics*

**Phyiscs **

a) Mixing high and low temperature is an irreversible process. You cannot separate the equilibrated mixture into high and low temperature without performing work. Could you run the mixing process backwards? No way. b) Set the heat loss by the warm water equal to the heat ...
*Thursday, July 15, 2010 at 11:08am by drwls*

**Phyiscs**

Suppose you throw a stone straight up with an initial velocity of 27.0 m/s and, 5.5 s later you throw a second stone straight up with the same initial velocity. The first stone going down will meet the second stone going up. At what height above the point of release do the two...
*Wednesday, December 5, 2012 at 2:10pm by HENRY!*

**Phyiscs**

If the plane is frictionless, the block will rise a vertical height h so thet mgh equals the initial kinetic energy (1/2) mV^2. Thus h = V^2/(2g) = 0.81 m. The distance x that the block mov es up the track is h/sin22 = 2.2 m So your answer is correct. The block decelerates at ...
*Saturday, July 11, 2009 at 7:39pm by drwls*

**Phyiscs**

A bicyclist makes a trip that consists of three parts, each in the same direction (due north) along a straight road. During the first part, she rides for 22 minutes at an average speed of 6.80 m/s. During the second part, she rides for 36 minutes at an average speed of 5.20 m...
*Tuesday, October 5, 2010 at 7:20pm by Ash*

**Phyiscs**

the gravitational constant G =6.67•10⁻¹¹ N•m²/kg², Earth’s mass is M = 5.98•10²⁴kg, Earth’s radius is R = 6.38•10⁶ m. T=L/v F = m₁•m₂/R= G•m•M/(2.07R) ² F=ma=m•v²/(2.07R) G•m•M/(2.07R)² =m•v²/(2.07R) v=...
*Sunday, June 30, 2013 at 8:50pm by Elena*

**phyiscs**

an means n a's multiplied together. For example: 56 = 5*5*5*5*5*5=15625 so 1.5*1013 means 1.5*10*10*10*10*10*10*10*10*10*10*10*10*10 =1.5*10000000000000 =15000000000000 =15,000,000,000,000
*Friday, October 29, 2010 at 8:35am by MathMate*

**phyiscs help please**

A 3.00*10^2 N force is pulling an 80.0 kg refrigerator across a horizontal surface. The force acts at an angle of 18.0° above the surface. The coefficient of kinetic friction is 0.200, and the refrigerator moves a distance of 8.00 m. (a) Find the work done by the pulling force...
*Friday, October 29, 2010 at 10:37am by Anonymous*

**phyiscs**

H=gt²/2 t =sqrt(2H/g) = sqrt(2•81/9.8)=4.07 s h=(1-0.28)H =58.32 s t₁ =sqrt(2h/g) =3.45 s. t₂=4.07 – 3.45 = 0.62 s. v₁=gt₁ =9.8•3.45 =33.81 m/s v₂ = gt₂ =9.8•4.07 = 39.89 m/s
*Thursday, September 12, 2013 at 4:07pm by Elena*

**Phyiscs **

Please show work You decide to take a nice hot bath but discover that your thoughtless roommate has used up most of the hot water. You fill the tub with 270 kg of 30.0°C water and attempt to warm it further by pouring in 5.00 kg of boiling water from the stove. (a) Is this a ...
*Thursday, July 15, 2010 at 11:08am by Anonymous*

**phyiscs**

How do I do these? Draw a free-body diagram for each of the following objects? a. a projectile in motion in the presence of air resistance b. a rocket leaving the launch pad with its engines operating c. a heavy crate being pushed across a rough surface a. mg is down, Ff is ...
*Tuesday, December 5, 2006 at 11:30pm by Anonymous*

**Phyiscs**

A wooden box with a mass of 10.0kg rests on a ramp that is inclined at angle of 25 degrees to the horizontal. A rope attached to the box runs parallel to the ramp and then passes over a frictionless pulley. A bucket with a mass of m hangs from the end of the rope. The ...
*Thursday, February 6, 2014 at 5:20pm by Lupita*

**Phyiscs - due at 11PM EST!!**

Two identical conducting spheres, fixed in place, attract each other with a force of 0.114 N when their center to center separation is 45.00 cm. The spheres are then connected by a thin conducting wire. When the wire is removed, the spheres have a net positive charge and repel...
*Tuesday, April 12, 2011 at 10:36pm by Bill*

**ap phyiscs**

A bowler throws a bowling ball of radius R=11 cm down a lane. The ball slides on the lane, with initial speed v(of the center of mass)=7 m/s and initial angular speed =0. The coefficient of kinetic friction between the ball and the lane is .25. The kinectic frictional force fk...
*Sunday, February 10, 2008 at 8:57pm by kristen*

**Phyiscs**

weight component down slope = 98.1 sin 25 = 41.5 N weight component normal to ramp = 98.1 cos 25 = 88.9 N max static friction = 88.9*.5= 44.5 N initial weight of bucket = 2*9.81 = 19.6 N force up ramp = 19.6 N force down ramp = 41.5 N Net force before friction down ramp = 41.5...
*Thursday, February 6, 2014 at 5:20pm by Damon*

**phyiscs**

It is explained in detail here http://farside.ph.utexas.edu/teaching/jk1/lectures/node82.html The important point is that an antenna that is much shorter than the wavelength will have a radiation resistance that will be far less than the internal radiation. Then for every ...
*Friday, May 29, 2009 at 1:02pm by Count Iblis*

**Phyiscs**

The height of the first stone is h₀=v₀²/2g=27²/2•9.8 = 37.2 m. v=v₀-gt, v=0 => the time of the upward motion is t= v₀/g =27/9.8=2.8 s. The 1st stone was falling down during t₁=5.5-2.8 = 2.7 s, when the 2nd stone started. The 1st stone...
*Wednesday, December 5, 2012 at 2:10pm by Elena*

**Phyiscs**

http://www.jiskha.com/search/index.cgi?query=+A+bicyclist+makes+a+trip+that+consists+of+three+parts%2C+each+in+the+same+direction+%28due+north%29+along+a+straight+road.+During+the+first+part%2C+she+rides+for+22+minutes+at+an+average+speed+of+6.80+m%2Fs.+During+the+second+part%...
*Tuesday, October 5, 2010 at 7:20pm by bobpursley*

Pages: **1**