Wednesday
April 23, 2014

Homework Help: Science: Physics

Recent Homework Questions About Physics

Post a New Question | Current Questions

Physics
A 1.50 ✕ 103-kg car starts from rest and accelerates uniformly to 19.3 m/s in 11.7 s. Assume that air resistance remains constant at 400 N during this time. (a) Find the average power developed by the engine. W (b) Find the instantaneous power output of the engine at t...
Wednesday, February 26, 2014 at 1:15pm

Physics
When a 2.00-kg object is hung vertically on a certain light spring described by Hooke's law, the spring stretches 3.17 cm. (a) What is the force constant of the spring? N/m (b) If the 2.00-kg object is removed, how far will the spring stretch if a 1.00-kg block is hung on ...
Wednesday, February 26, 2014 at 1:14pm

Physics
skier of mass 79 kg is pulled up a slope by a motor-driven cable. (a) How much work is required to pull him 80 m up a 30° slope (assumed frictionless) at a constant speed of 3.4 m/s? 1 J (b) What power (expressed in hp) must a motor have to perform this task?
Wednesday, February 26, 2014 at 1:13pm

ap physics
skier of mass 79 kg is pulled up a slope by a motor-driven cable. (a) How much work is required to pull him 80 m up a 30° slope (assumed frictionless) at a constant speed of 3.4 m/s? 1 J (b) What power (expressed in hp) must a motor have to perform this task?
Wednesday, February 26, 2014 at 1:12pm

physics
The builders of the pyramids used a long ramp to lift 21000-kg (21-ton) blocks. If a block rose 1.0 m in height while traveling 21 m along the ramp’s surface, how much uphill force was needed to push it up the ramp at constant velocity?
Wednesday, February 26, 2014 at 12:12pm

physics
I'm driving along at a constant speed in my 3 meter long car when I notice that I am accidentally driving through a red light. If the rear of my car passes under the light 0.3 seconds after the front of my car, how fast am I driving in m/s?
Wednesday, February 26, 2014 at 11:58am

physics
If a race car’s velocity increases from 4 m/s to 36 m/s over a 4 s time interval, its average acceleration would be 10 m/s2.
Wednesday, February 26, 2014 at 11:16am

Physics
A thundercloud has an electric charge of 43.2 C near the top of the cloud and -38.7 C near the bottom of the cloud. The magnitude of the electric force between these two charges is 3.95 x 10 ^6 N. What is the average separation between these charges? Can anyone help?
Wednesday, February 26, 2014 at 11:05am

Physics
Did you find the answer for this?
Wednesday, February 26, 2014 at 11:03am

Physics
Amber, did you get the answer for this?
Wednesday, February 26, 2014 at 11:03am

PHYSICS
Did anyone get the answer for this?
Wednesday, February 26, 2014 at 11:02am

physics
h = (1/2)(9.8)(4.59)^2
Wednesday, February 26, 2014 at 10:38am

PHYSICS !!
momentum before = momentum just after .045 * 165 = 2.045 * Vi solve for Vi, the inital velocity fater collision Ke = (1/2)(2.045)(Vi^2) initial kinetice energy of bullet-block system That Ke will be the work done by friction: Ke = F * d = mu m g * d m cancels so so 0.4 (9.81) ...
Wednesday, February 26, 2014 at 10:37am

Honors Physics
1
Wednesday, February 26, 2014 at 10:13am

physics
A rock is dropped off of a bridge into the water below. If the initial velocity was zero, and the well is on Earth (g = 9.8 m/s2), and you see the splash 4.59 seconds after the rock was dropped, how high was the bridge above the water? Give your answer in meters, to the ...
Wednesday, February 26, 2014 at 9:24am

PHYSICS !!
oh yea the bullet was embedded to the block after it hits
Wednesday, February 26, 2014 at 8:18am

PHYSICS !!
A 45.0g bullet is fired on a 2.0kg wooden block which is resting on a horizontal surface with a coefficient friction of 0.4 . If the speed of the bullet is 165m/s when it hits the block. Determine the maximum horizontal distance of the block will reach
Wednesday, February 26, 2014 at 8:09am

physics
Two insulated wires, each 2.70 m long, are taped together to form a two-wire unit that is 2.70 m long. One wire carries a current of 7.00 A; the other carries a smaller current I in the opposite direction. The two wire unit is placed at an angle of 77.0° relative to a ...
Wednesday, February 26, 2014 at 1:07am

physics
A proton, traveling with a velocity of 4.9 106 m/s due east, experiences a magnetic force that has a maximum magnitude of 7.4 10-14 N and a direction of due south. What are the magnitude and direction of the magnetic field causing the force?
Wednesday, February 26, 2014 at 12:16am

physics
The drawing shows a parallel plate capacitor that is moving with a speed of 30 m/s through a 3.1 T magnetic field. The velocity vector v is perpendicular to the magnetic field. The electric field within the capacitor has a value of 170 N/C, and each plate has an area of 7.5 10...
Wednesday, February 26, 2014 at 12:07am

Physics
An airplane pilot fell 355 m after jumping without his parachute opening. He landed in a snowbank, creating a crater 1.4 m deep, but survived with only minor injuries. Assume that the pilot's mass was 81 kg and his terminal velocity was 50 m/s. (a) Estimate the work done ...
Wednesday, February 26, 2014 at 12:02am

Physics Please help!
If it requires 5.5J of work to stretch a particular spring by 2.3cm from its equilibrium length, how much more work will be required to stretch it an additional 4.5cm ? Express your answer using two significant figures. W=_____ J?
Tuesday, February 25, 2014 at 11:59pm

Physics
well that doesn't look readable. the answer should still be right but I'll rewrite how I did the math Cfs = mv^2/rFn = ((2πr/T)^2)/r(g) = (4(π^2)r)/g(T^2) Cfs = 4(π^2)(0.159 m) / (9.8 m/s^2)(1.50 s)^2 = 0.28467
Tuesday, February 25, 2014 at 11:21pm

Physics
Static Friction Coefficient = Cfs For of Static Friction = Fs Normal Force = Fn Centripetal Force = Fc mass = m radius = r speed = v period of time = T Fs = Cfs * Fn so Cfs = Fs/Fn Fc = Fs and since Fs = mv^2/r Cfs = Fs/Fn = mv^2/r*Fn v = 2πr/T and Fn = mg so.... mv^2 (2...
Tuesday, February 25, 2014 at 11:17pm

Physics
Three vectors are given by: a=0i+oj+4.0k b=3.0i+-3.0j+-1.0k c=1.0i+2.0j+-1.0k a) Find a(bxc) b) Find a(b+c)
Tuesday, February 25, 2014 at 11:09pm

Physics
A wooden block of mass m = 2.3 kg starts from rest on an inclined plane sloped at an angle 26 degrees from the horizontal. The block is originally located 1.9 m from the bottom of the plane. Assume the inclined plane is friction less. 1)What is the magnitude of the component ...
Tuesday, February 25, 2014 at 10:16pm

physics
A 2.284 km car is moving down a road with a slope of 13% at a constant speed of 11 m/s. What is the direction and magnitude of the frictional force?
Tuesday, February 25, 2014 at 9:57pm

UK/Physics
Yes, the expression of Joules is generally very large when dealing with human beings moving slow, or small projectiles moving fast.
Tuesday, February 25, 2014 at 9:53pm

physics
A jet flying at 138 m/s banks to make a horizontal circular turn. The radius of the turn is 3810 m, and the mass of the jet is 2.40 × 105 kg. Calculate the magnitude of the necessary lifting force.
Tuesday, February 25, 2014 at 9:50pm

physics
h = Yo*t + 0.5g*t^2 = 34.3 39.2t - 4.9t^2 = 34.3 -4.9t^2 + 39.2t - 34.3 = 0 t = 1 s. (Used Quad. Formula).
Tuesday, February 25, 2014 at 9:35pm

physics
a 2250 kg car is traveling at 20 m/s to the west. the force required to stop the car at 7890 N to the east. How long will it take the car to stop? How far would the car move before stopping?
Tuesday, February 25, 2014 at 9:28pm

physics
A woman is riding a Jet Ski at a speed of 20 m/s and notices a seawall straight ahead. The farthest she can lean the craft in order to make a turn is 20°. This situation is like that of a car on a curve that is banked at an angle of 20°. If she tries to make the turn ...
Tuesday, February 25, 2014 at 9:20pm

Physics
9.7N
Tuesday, February 25, 2014 at 9:03pm

Physics 130
A 20kg child slides down a long slide in a playground. She starts from rest at a height of 25m. When she is part way down the slide at a height of 10m, she is moving at 16m/s. Calculate the mechanical energy lost due to friction.
Tuesday, February 25, 2014 at 8:59pm

Physics 130
You are welcome :)
Tuesday, February 25, 2014 at 8:40pm

physics
great, thanks so much!
Tuesday, February 25, 2014 at 8:36pm

Physics 130
Thank you so much!
Tuesday, February 25, 2014 at 8:26pm

Physics
with this problem, we don have the weight but we do no that the tibia of the insect is in the y-axis in relations to theta so: a)6Tsin40=mg T=mg/6sin40 --> expressing this as the bugs weight, gives us T/mg = 0.3 b) note that the insect legs have been slightly bent so as the...
Tuesday, February 25, 2014 at 8:26pm

physics
the fricioal force is upward. it's magnitude is equal to the quantity I specifid.
Tuesday, February 25, 2014 at 8:25pm

Physics 130
it is the downward component of the 20 N force you are pushing.
Tuesday, February 25, 2014 at 8:24pm

physics
without a diagram, this makes no sense.
Tuesday, February 25, 2014 at 8:22pm

Physics 130
can you explain the 20sin30?
Tuesday, February 25, 2014 at 8:18pm

physics
I'm sorry, I wrote the question wrong! Correctly, the questions reads: A 1.761 km car is moving down a slope of 12% at a constant velocity of 17 m/s. What I'd the direction and magnitude of the frictional force? Again, sorry!
Tuesday, February 25, 2014 at 8:18pm

Physics 130
Is it on a level road? If so m g + 20 sin 30 15 * 9.81 + 10
Tuesday, February 25, 2014 at 8:15pm

Physics 130
It says nothing about friction, so assume its frictionless.
Tuesday, February 25, 2014 at 8:15pm

Physics 130
normal force downward: mg+ 20sin30
Tuesday, February 25, 2014 at 8:14pm

Physics 130
you push a 15kg cart with a force of 20N, 30 degrees below the horizontal. what is the normal force? Please help test tomorrow.
Tuesday, February 25, 2014 at 8:13pm

physics
constant speed? that means the force of gravity down the slope is exactly equal to the force of friction, so the gravity force down the slope is... mgSinTheta
Tuesday, February 25, 2014 at 8:11pm

physics
A 1.761 km car is moving down a road with a slope (grade) of 12% at a constant direction and magnitude of the frictional force? Please show step by step if possible, I am extremely lost! Thanks!
Tuesday, February 25, 2014 at 8:05pm

Physics
V = Vo + a*t = 27.8 0 + a*3.4 = 27.8 a = 8.18 m/s^2. V = Vo + a*t = 0 + 8.18*5.1 = 41.70 m/s.
Tuesday, February 25, 2014 at 8:03pm

Physics
Range = Vo^2*sin(2A)/g 200^2*sin(160)/9.8 = 1396 m.
Tuesday, February 25, 2014 at 7:20pm

physics
The pulley is light and frictionless. Find the mass M1, given that M2 (7.00 kg) is moving downwards and accelerates downwards at 3.01 m/s2, that θ is 15.0°, and that μk is 0.270.
Tuesday, February 25, 2014 at 7:17pm

Physics
If they stick together then momentum is conserved x momentum before = m v y momentum before = m v x momentum after = 2 m U cos theta y momentum after = 2 m U sin theta so 2 U cos theta = v 2 U sin theta = v or cos theta = sin theta so theta = 45 degrees cos theta = cos 45 = ...
Tuesday, February 25, 2014 at 7:13pm

physics
111
Tuesday, February 25, 2014 at 7:10pm

Physics
two cars of equal mass with equal speeds traveling perpendicular to one another collide completely inelastically. what percentage of the cars' total energy is lost in the collision?
Tuesday, February 25, 2014 at 7:07pm

Physics
See Related Questions: Wed,2-19-14,9:27 PM.
Tuesday, February 25, 2014 at 7:07pm

physics
Range = Vo^2*sin(2A)/g = 301.5 m. Vo^2*sin(50)/g = 301.5 .07817Vo = 301.5 Vo^2 = 3857 Vo = 62.10 m/s.
Tuesday, February 25, 2014 at 6:57pm

physics
To calculate the required force, we'll need to know the force of friction or the coefficient of frictional force.
Tuesday, February 25, 2014 at 6:40pm

Physics
ritzi as in spikey sea urchins? If a collision is elastic, no kinetic energy is lost. That is what an elastic collision means.
Tuesday, February 25, 2014 at 6:39pm

Physics
two cars of equal mass with equal speeds traveling perpendicular to one another collide completely in elastically. what percentage of the cars' total energy is lost in the collision?
Tuesday, February 25, 2014 at 6:35pm

physics
A. F = Fp = 71.5*sin24.1 = 29.20 N. B. Fn = 71.5*cos24.1 = 65.27 N. = Normal force = Force perpendicular to the plane Fs = u*Fn = 0.26 * 65.27 = 16.97 N = Force of static friction. F-Fp-Fs = m*a = m*0 = 0 F-29.20-16.97 = 0 F = 46.17 N. C. Fk = u*Fn = 0.13 * 65.27 = 8.49 N. = ...
Tuesday, February 25, 2014 at 6:27pm

physics
A person of mass M lies on the floor doing leg raises. His leg is 0.85m long and pivots at the hip. Treat his legs (including feet) as uniform cylinders, with both legs comprising 34.5% of body mass, and the rest of his body as a uniform cylinder comprising the rest of his ...
Tuesday, February 25, 2014 at 5:53pm

physics
Cheetahs can sustain speeds of 25 m/s over short distances. One of their prey is Thomson's gazelle, with top speed about 22 m/s. If a 52kg cheetah running southward at top speed grabs and holds onto a 23kg gazelle running westward at 22 m/s, find the velocity of these ...
Tuesday, February 25, 2014 at 5:52pm

physics
6
Tuesday, February 25, 2014 at 5:15pm

physics
The oxygen taken in by the body reacts with fats, carbohydrates, and protein, liberating energy internally at a rate of about 2.12×104 J /liter. If a 85.4 kg man requires 73.0 W of power even while sleeping, what is his rate of oxygen consumption?
Tuesday, February 25, 2014 at 5:00pm

physics
Are you not given the magnetic field strength, B?
Tuesday, February 25, 2014 at 4:15pm

Physics
1) Car - S = 50 (50m to travel to reach truck since truck is moving away at a constant acceleration) u = o a = 3 t = ? S = ut + 0.5*a*t^2 50 = 0 + 0.5(3)t^2 t = sqr(100/3) = 5.77s 2) S = 50 u = o v = ? a = 3 t = 5.77 v = u + at v = 0 + 3*5.77 v = 17.3 m/s 3) S = - u = o v = ? ...
Tuesday, February 25, 2014 at 4:06pm

Physics
a car and a truck start from rest at the same instant with the car initially 50m behind the truck. The truck has a constant acceleration of 2m/s^2 and the car has a constant acceleration of 3m/s^2. The car overtakes the truck after how many seconds? At what speed is the car ...
Tuesday, February 25, 2014 at 3:49pm

Physics
If the gravitational force on you is 670N on the earth, how strong is the gravitational force on you on the surface of a neutron star that has the same mass as our sun and a diameter of 20.0km ? Take the mass of the sun to be ms = 1.99×1030kg , the gravitational constant...
Tuesday, February 25, 2014 at 3:13pm

Physics
Consider the earth following its nearly circular orbit (dashed curve) about the sun.(Figure 2) The earth has mass mearth=5.98×1024kg and the sun has mass msun=1.99×1030kg. They are separated, center to center, by r=93millionmiles=150millionkm. What is the size of ...
Tuesday, February 25, 2014 at 3:09pm

physics
A 0.272- kg coffee mug rests on a table top 0.71 m above the floor. What is the potential energy of the mug with respect to the floor?
Tuesday, February 25, 2014 at 3:03pm

physics
See previous post: Thu,2-20-14,5:05 PM.
Tuesday, February 25, 2014 at 2:48pm

physics 111
a 50kg boy suspends himself from a point on a rope tied horizontally between two vertical poles.the two segments of the rope are then inclined at angle 30 degrees and 60degrees to the horizontal.the tensions in the segments of the rope is?
Tuesday, February 25, 2014 at 2:47pm

Physics
Incomplete.
Tuesday, February 25, 2014 at 2:44pm

physics
A block rests on a horizontal frictionless surface. A string is attached to the block, and is pulled with a force of 60.0 N at an angle θ above the horizontal. After the block is pulled through a distance of 2.00 m, its speed is 2.70 m/s, and 43.0 J of work has been done ...
Tuesday, February 25, 2014 at 1:09pm

physics
A 0.349 kg particle slides around a horizontal track. The track has a smooth, vertical outer wall forming a circle with a radius of 1.68 m. The particle is given an initial speed of 8.66 m/s. After one revolution, its speed has dropped to 6.05 m/s because of friction with the ...
Tuesday, February 25, 2014 at 1:07pm

physics
A 1,160-N crate is being pushed across a level floor at a constant speed by a force vector F of 310 N at an angle of 20.0° below the horizontal, as shown in the figure (a) below.
Tuesday, February 25, 2014 at 12:33pm

physics
Two spheres are mounted on identical horizontal springs and rest on a frictionless table, as in the drawing. When the spheres are uncharged, the spacing between them is 0.05 m, and the springs are unstrained. When each sphere has a charge of +1.6 £gC, the spacing doubles...
Tuesday, February 25, 2014 at 12:07pm

physics - Huh ?
I have no idea because I do not know the mass or the spring constant.
Tuesday, February 25, 2014 at 12:05pm

Physics
A 7.65- g bullet from a 9-mm pistol has a velocity of 329.0 m/s. It strikes the 0.625- kg block of a ballistic pendulum and passes completely through the block. If the block rises through a distance h = 29.75 cm, what was the velocity of the bullet as it emerged from the block?
Tuesday, February 25, 2014 at 10:40am

physics
An accelerometer is a device that uses the extension of a spring to measure acceleration in terms of Earth's gravitational acceleration (g). What is the approximate acceleration if this accelerometer spring is extended just 0.43 centimeters?
Tuesday, February 25, 2014 at 10:02am

Physics
The students made it to the bottom with out a problem but added 400 kg for a total of 455 kg and slides for 12.2 s across the surface of a frozen lake. If the coefficient of kinetic friction between the kid and the ice is 0.071, what is the change in the students momentum as ...
Tuesday, February 25, 2014 at 2:20am

physics
3m
Tuesday, February 25, 2014 at 1:11am

physics
A force of 1.24 N pushes against an object with a mass of 0.16 kg for 4.00 min. The object does not move. What is the work done on the object by the force?
Tuesday, February 25, 2014 at 12:10am

physics
8.1*10^4
Tuesday, February 25, 2014 at 12:06am

Physics
A 6.2 kg model rocket is traveling horizontally and due south with a speed of 20.3 m/s when it explodes into two pieces. The velocity of one piece, with a mass of 1.6 kg, is v1 = (-12 m/s)i + (30 m/s)j + (15 m/s)k, with i pointing due east, j pointing due north, and k pointing...
Monday, February 24, 2014 at 10:49pm

Physics
I got the correct answer for the thrower, but for the catcher to find the second velocity, I follow the formula but it still counts it as wrong. What could I be doing wrong?
Monday, February 24, 2014 at 10:46pm

physics
Fp=mg*sin16.6 = 509.6*sin16.6=145.6 N. = Force parallel to the ramp. Fn = 509.6*cos16.6 = 488.4 N. = Normal force = Force perpendicular to the ramp. d = Vo*t + 0.5a*t^2 = 3.98 m. 0 + 0.5a*4.1^2 = 3.98 8.405a = 3.98 a = 0.474 m/s^2. Fp-Fk = m*a 145.6 - Fk = 52*0.474 -Fk = 24.62...
Monday, February 24, 2014 at 10:36pm

physics
A 0.13 kg ball of dough is thrown straight up into the air with an initial speed of 18 m/s. The acceleration of gravity is 9.81 m/s2 .What is its momentum halfway to its max- imum height on the way up?
Monday, February 24, 2014 at 10:31pm

physics
the rotation of earth is a period of 86164 seconds. the earth has a radius of 6380 km. how fast would you be moving due to earths rotation at the equator? also how fast would you be moving at a latitude of 27 degrees north of the equator? also calculate the centripetal ...
Monday, February 24, 2014 at 10:19pm

physics
(a) rotation around sticky hinge (b) rotation of screw (c) rotation around fulcrum of lever
Monday, February 24, 2014 at 10:12pm

physics
Explain why should torques, not forces, play essential roles in the following actions. (a) open or close a door (b) tighten or loosen a screw using a wrench c) "Give me a place to stand, and I shall move the Earth with it"
Monday, February 24, 2014 at 10:09pm

physics
177 (12+32)/32 = 243 I get but anyway 177 (32 -32) = 0
Monday, February 24, 2014 at 9:51pm

Physics
60 *1000/3600 =16.7 m/s average speed during stop = 8.33 m/s time to stop t = 35/8.33 = 4.2 s acceleration = - 16.7/ 4.2 = 3.98 m/s^2 m a = mu m g mu = a/g 3.98 / g = .405
Monday, February 24, 2014 at 9:46pm

Physics
Vo=20mi/h * 5280Ft/mi*1h/3600s=29.33Ft/s a = (V^2-Vo^2)/2d a = (0-29.33^2)/40 = -21.51 Ft/s^2. V = Vo + a*t = 0 29.33 - 21.51*t = 0 21.51t = 29.33 t = 1.36 s. To stop.
Monday, February 24, 2014 at 9:43pm

physics
if I weigh 177 lb on a stationary scale and stand on that same scale inside an elevator going up at an acceleration of 12 ft/s^2 the scale will read 238lbs. if the elevator, still moving upwards, decelerates at the rate of 32 ft/s^2 what will the scale read?
Monday, February 24, 2014 at 9:42pm

physics
r^2/rearth^2 = 4/3 r = rearth *sqrt (1.33) = 1.15 rearth height = r - rearth = .15 rearth
Monday, February 24, 2014 at 9:39pm

Physics
A 1250 kg car travelling at 60.0 km/h comes to a sudden stop in 35 m. What is the coefficient of friction acting on the brakes?
Monday, February 24, 2014 at 9:36pm

physics
12 + 32 = 43 ft/s^2 177 * (43/32) = 238 pounds
Monday, February 24, 2014 at 9:34pm

physics
At what altitude the value of g becomes 3/4 of its value on the surface of earth?
Monday, February 24, 2014 at 9:31pm

Pages: <<Prev | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | Next>>

Post a New Question | Current Questions

Homework Help: Science

Search
Members