Physics - October 2007

At the surface of Jupiter's moon Io, the acceleration due to gravity is 1.81 . A watermelon has a weight of 52.0 at the surface of the earth. In this problem, use 9.81 for the acceleration due to gravity on earth.

2007-10-08 15:46:25 · 3 answers · asked by Natiphy2007 1

Did you do work? To answer this question, consider whether you applied a force parallel to the displacement of the moving end of the rubber band.

I got this part right it was simple but I just dont understand this part

Consider how the force applied to stretch the rubber band feels as you stretch it. Order from least to most force applied. (If B is the least, then A, then C, enter BAC.)

A) At the beginning of the stretch.
B) In the middle of the stretch.
C) At the end of the stretch.

2007-10-08 15:29:42 · 1 answers · asked by Anonymous

I don't need answers I am just stuck on how to formulate the correct equation

The magnitudute of each force is 164 N the fore on the right is applied at an angle of 44 degrees. he mass of an object is 16 kg
The coefficient of friction is .268 the acceleration of gravity is 9.8m/s/s

Find the resulting acceleration

the second problem


An 863N crate is being pushed across level floor by a force of 313 N at an agle of 21 degrees above the horizontal. The coefficient of kinetic friction between the crate and the floor is .2 the acceleration of the gravity is 9.81 m/s/s

What is the acceleration of the box?


Thank you for any help

I DO NOT NEED AN ANSWER, JUST HOW WOULD I MANIPULATE THE EQUATIONS TO SOLVE THESE PROBLEMS THANK YOU

2007-10-08 15:20:19 · 2 answers · asked by Anonymous

a large cube (mass = 24 kg) is being accelerated across a horizontal frictionless surface by a horizontal force P. A small cube (mass = 2.6 kg) is in contact with the front surface of the large cube and will slide downward unless P is sufficiently large. The coefficient of static friction between the cubes is 0.71. What is the smallest magnitude that P can have in order to keep the small cube from sliding downward?

i know the equation is P-Fn=ma

Fn is the natural forcei know that you are supposed to add the natural force some where but im not sure where.

that is as far as i could get with this problem. see, i really did try to do it. i just can't finish it. please, PLEASE help me. i really am trying!

2007-10-08 15:08:17 · 3 answers · asked by Elizabeth 3

I don't know if this is a solvable question or not but here's the question.

A rock is thrown directly upward from the edge of the roof of a building that is 56.3 meters tall. The rock misses the building on its way down, and is observed to strike the ground 4.00 seconds after being thrown. Take the acceleration due to gravity to have magnitude 9.80 m/s^2 and neglect air resistance. With what speed was the rock thrown?

it just seems like i'm not given enough information. any suggestions on how to figure this out.

2007-10-08 15:07:26 · 1 answers · asked by shadoyaj 4

ok I have a generator and a resistor connected to a transformer. 30 ohm resistor with 11 loops on the transformer. the generator oscillates between 500 and -500 v and has 5 loops.

what is the average power on the resistor

2007-10-08 15:04:09 · 1 answers · asked by cheski88 1

A child in danger of drowning in a river is being carried downstream by a current that has a speed of 2.50 km/h. The child is 0.600 km from shore and 0.800 km upstream of a boat landing when a rescue boat sets out.

(a) If the boat proceeds at its maximum speed of 17.0 km/h relative to the water, what heading relative to the current should the pilot take?
__________° relative to the direction of the current
(b) What angle does the boat velocity make with the current?
__________° relative to the direction of the current
(c) How long does it take the boat to reach the child?
__________s



I have no idea how to do this. Could anyone help me?
Thanks.

2007-10-08 14:49:46 · 1 answers · asked by The Rationalist 2

A flowerpot is dropped from a balcony of an apartment 28.5m above the ground. At a time of 1.00s after the pot is dropped, a ball is thrown vertically downward from the balcony one storey below, 26.0m above the ground. The initial velocity of the ball is 12m/s (down). Does the ball pass the flowerpot before striking the ground? If so, how far above the ground are the two objcts when the ball passes the flowerpot?

2007-10-08 14:43:03 · 2 answers · asked by mahdi_end2006 2

2007-10-08 14:35:56 · 1 answers · asked by KRISTINE 1

A frictionless roller coaster is given an initial velocity of V(intial) at height h= 26 m. The radius of curvature of the track at point A is R=38 m. The acceleration of gravity is 9.8 m/s^2
Find the maximum value of Vinitial so that the rooler coaster stays on the track at solely becasue of gravity. Answer in units of m/s.
Please help me with this problem, i have been tried to work it out many time but it wasn't correct

2007-10-08 14:07:41 · 1 answers · asked by Tony 1

A ball is thrown upward from the ground with an initial speed of 31 m/s. At the same instant, a ball is dropped from rest from a building 15 m high. After how long will the balls be at the same height?
s

I tried to graph the movment of the two objects and and used the point of intersection as the awnser, but the webassign program said i was wrong. Any help would be great.

2007-10-08 14:07:35 · 1 answers · asked by Anonymous

( to protect an egg )

2007-10-08 14:06:45 · 1 answers · asked by lance b 1

Consider the acceleration of gravity to be
10 m=s2 :
What is the magnitude of the instantaneous
velocity (speed) of a freely falling object 18 s
after it is released from a position of rest?
Answer in units of m=s.

The answer to that is 180 m/s

how do i figure out teh avg speed?

2007-10-08 14:05:27 · 1 answers · asked by Jarod S 2

Does anyone know these things about Piezoelectricity?

1) If you want to see the effects of Piezoelectric crystals, should you place them them in a circuit (between two piece of wire, connected to an ammeter. Then, place a lot of force on the Piezoelectric crystal, and see what the ammeter reports? Or will that not work? Thanks.

2) A Piezoelectric crystal generates electricity when something strikes it, right? But the electricity needs to be conducted through the crystal, right? So is there the faintest possibility that changing the temperature will change the amount of current (like in conductor's resistances)?

THANKS!

2007-10-08 13:39:54 · 1 answers · asked by magixter 2

2007-10-08 13:22:06 · 1 answers · asked by brian_rambadan 2

2007-10-08 13:12:03 · 4 answers · asked by Anonymous

High-voltage power lines are a familiar sight throughout the country. The aluminum (resistivity = 2.82 x 10^-8 Ohm *m) wire used for some of these lines has a cross-sectional area of 4.4 x 10^-4 m^2. What is the resistance of 12 kilometers of this wire?

2007-10-08 13:10:37 · 2 answers · asked by Anonymous

2007-10-08 13:04:18 · 15 answers · asked by Anonymous

A 3.40 kg box is sliding across the horizontal floor of an elevator. The coefficient of kinetic friction between the box and the floor is 0.410. Determine the kinetic frictional force that acts on the box for each of the following cases.
(a) the elevator is stationary
___N
(b) the elevator is accelerating upward with an acceleration whose magnitude is 1.40 m/s2
___N
(c) the elevator is accelerating downward with an acceleration whose magnitude is 1.40 m/s2
___N

2007-10-08 13:01:15 · 1 answers · asked by Marianna E 1

It's well established that it takes an amount of time (about 3 minutes) for a photon to reach the earth from the sun. Relativity says that as an object approaches the speed of light that time, for the object, slows. So it follows that a photon leaving the sun at t=0 arrives at the earth at t=0. This is contradicted obviously by observable evidence. How is this so?

2007-10-08 12:59:18 · 4 answers · asked by Anonymous

i have just started physics. every now and then, i will see a problem and it asks for the dirrection and magnitude or something and magnitude, or just magnitude. what is magnitude. please make your answer idiot proof please.

thank you!

2007-10-08 12:26:57 · 14 answers · asked by Elizabeth 3

d=0.02(3v*v + 20v + 1000) where v=m/s
determine the speed at which the safe stopping distance is 30m, correct to one decimal.

2007-10-08 12:25:43 · 1 answers · asked by yeshila 1

science pop quiz!

2007-10-08 12:22:56 · 4 answers · asked by Anonymous

This is from a test review and this is the only one I am having trouble with... If someone could please explain it to me, I'd be very grateful. :)

Babe Ruth hit a home run that was estimated to have landed 180m from home plate and to have reached a height of 21.3m. Find the initial velocity of the baseball and the angle it made with the horizontal.

We have to use a combination of any of these equations:
x=vt
final v = initial v +at
y = (initial v)t +.5a(t^2)
(final v)^2= (initial v)^2 + 2ay

a=9.81 m/s^2

And he gave us the answer to check ourselves, and it's 48 m/s at 25 degrees.

Thank you!

2007-10-08 11:31:38 · 3 answers · asked by Anonymous

Would it be possible to connect the lightning rods in buildings to the electricity grid or some kind of capacitor, so that when lightning strikes we can harness it?

2007-10-08 11:08:38 · 13 answers · asked by statstastic 2

If a really strong but very light material were available to contain a vacuum, would it float away?

2007-10-08 11:05:04 · 7 answers · asked by Never say Never 5

a 81.0 kg person is standing on a scale in an elevator. what is the apparent weight when the elevator is

(a) accelerating upward with an acceleration of 1.80 m/s^2?

(b) moving upward at a constant speed?

(c) accelerating downward with an acceleration of 2.00 m/s^2?

i really am stuck. please help me. i don't know how to do this!!

please, Please, PLEASE help me!!!

thank you!

2007-10-08 10:56:03 · 2 answers · asked by Elizabeth 3

2007-10-08 10:55:32 · 2 answers · asked by Anonymous

A 800 N force is exerted on the 60 kg box toward the 90 kg box. Calculate:
a) The accleration of the boxes.
b) The magnitude of the action / reaction forces between the boxes.

2007-10-08 10:19:31 · 1 answers · asked by Anonymous

a) what is its speed when it is at maximum height?
b) how far the launch site will kiwi strike the ground?
c) what will be its speed upon impact upon impact with the ground?

2007-10-08 10:13:34 · 1 answers · asked by Anonymous