Physics - November 2007

A car travels at 38 m/s for 7 s. It then speeds up with a constant acceleration of 5 m/s^2 for 22 s. At the end of this time, what is its velocity in m/s?

2007-11-01 13:36:32 · 1 answers · asked by kickitup21 1

We know that in real world, extremity does not exist. When something approach to an extreme, it transfers to another thing. For example, we can trace adult to its childhood, to its birth, to its embryonic cell. But can we trace it any further down to 10^(-30)? No. It cannot be reduced in size further (in terms of life), because it transfers - the zygote comes from fertilization of sperm and egg cells, which come from parents (adults), and we then start the cycle all over again.

So why do some scientists believe there’s something call Big Bang and some others believe the Universe is infinite?

2007-11-01 13:09:40 · 4 answers · asked by Joe 1

Find the area of the square not covered by the circle to the nearest tenth

2007-11-01 12:58:40 · 1 answers · asked by Anna 1

An underwater swimmer observes that a beam of sunlight in the water makes an angle of 17.7° with the vertical. The index of refraction for water is equal to 1.33. Assuming the surface of the water is level, determine the beam's angle as it enters the water.

2007-11-01 12:58:01 · 1 answers · asked by Kelly 1

An elephant and mouse would both have zero weight in gravity-free space. if they were moving toward you with the same speed, would they bump into you wiht the same effect? Explain.

It tried looking in the book for help but didnt understand.

2007-11-01 12:57:30 · 3 answers · asked by Catherine 2

a 2.0-g particle moving at 8.0 m/s makes a perfectly elastic head-on collision with a restiing 1.0 -g object. find the speed of each particle after the collision and find the stationary speed of each particle after the collision if the stationary particle has a mass of 10g.

2007-11-01 12:40:04 · 1 answers · asked by confusedkid 3

A string is attached to three masses 4kg, 1kg and 6kg and the acceleration of gravity is 9.8m/s^2. A pulley has no mass and no friction and the string has no mass. The distance between the 1kg and 4kg is 2m and the string is 24cm long. The tension T1 is between the 4kg and 1kg, and the tension T2 is between 2kg and the pulley, both masses are on the left side and T3 is on the right side with 6kg. The 4kg is below the 1kg on the left side. I need to find the tension between the block with mass of 4kg and 1kg on the left hand side of the pulley and the answer has to be in units of N. Could someone explain how I can answer this.

2007-11-01 12:33:50 · 4 answers · asked by kira 2

A swimmer wears a heavy belt to make her average density exactly equal to the density of water. Her mass, including the belt, is 55 kg.
(a) What is the swimmer's weight in newtons? (total weight, including belt)
_____ N
(b) What is the swimmer's volume in m^3?
_____m^3
(c) At a depth of 2 m below the surface of a pond, what buoyant force acts on the swimmer?
______N
What net force acts on her?
_____N

2007-11-01 12:18:13 · 2 answers · asked by TheLostOne 3

idk how much 1 m&m weighs and i need it in metric

2007-11-01 12:15:23 · 3 answers · asked by Onlyone 1

1.> Two air track carts move toward one another on an air track. Cart 1 has a mass of 0.53 kg and a speed of 0.9 m/s. Cart 2 has a mass of 0.56 kg.
(a) What speed must cart 2 have if the total momentum of the system is to be zero?

(b) Since the momentum of the system is zero, does it follow that the kinetic energy of the system is also zero?
yes or no
(c) Verify your answer to part (b) by calculating the system's kinetic energy.

2.> A honeybee with a mass of 0.175 g lands on one end of a popsicle stick. After sitting at rest for a moment, the bee runs toward the other end with a velocity 1.29 cm/s relative to the still water. What is the speed of the 4.65 g stick relative to the water? (Assume the bee's motion is in the negative direction.

2007-11-01 12:09:27 · 1 answers · asked by Anonymous

how do you find acceleration? is it like distance over time... or distance times time... idk ...pleasee helpp!

2007-11-01 12:01:03 · 3 answers · asked by Anonymous

2007-11-01 11:59:23 · 1 answers · asked by Patricia w 1

Use Bernoulli's equation to estimate the upward force on an airplane's wing if the average flow speed of air is 180 m/s above the wing and 155 m/s below the wing. The density of the air is 1.2 kg/m3 and the area of each wing surface is 27 m2

2007-11-01 10:54:44 · 1 answers · asked by Lzoza A 1

5.4 x 10^-3 m and 5.0 x 10^-2 m, respectively. If the height difference between the input piston and the output plunger can be neglected, what force is applied to the trash when the input force is 334 N.

2007-11-01 10:53:06 · 1 answers · asked by Anonymous

The density of seawater is 1025 kg/m3.

a) If an underwater vehicle were to explore such a depth, what force would the water exert on the vehicle's observation window (radius = 0.11 m)?

b) For comparison, determine the weight of a jetliner whose mass is 1.5 x 10^5 kg.

2007-11-01 10:49:13 · 2 answers · asked by Anonymous

A bullet having a mass of 5g is fired horizontally into a wooden block of 2.5 kg mass that is sitting at rest on a horizontal surface. The coefficient of kinetic friction between the block and the surface is μk = 0.25. The bullet comes to rest in the wooden block, which moves a distance of 2 m along the surface. 1) How much work did the bullet do in pushing the block? 2) What was the speed of the bullet when it hit the block? 3) How much kinetic energy was absorbed by the block (i.e. how much energy was not available to push the block)?

2007-11-01 10:47:40 · 1 answers · asked by Laduch 2

If a ball is sitting on the ground, would it have no potential energy, maximum potential energy, or something else? Would it have no kinetic energy or maximum kinetic energy?

2007-11-01 10:36:09 · 5 answers · asked by Saffy 2

2007-11-01 10:17:46 · 4 answers · asked by candice 2

if you have courage and a tight grip you can yank a tablecloth out from under the dishes on a table. What is the longest time in which the cloth can be pulled out so that a glass 6 inches from the edge comes to rest before falling off the table? Assume that the coefficient of friction of the glass sliding on the tablecloth or sliding on the tabletop is .5

2007-11-01 10:12:28 · 2 answers · asked by blugh 2

A weight of 1200 N rests on a lever at a point 0.50 m from a support . On the same side of the support, at a distance of 3.0 m from it, an upward force with magnitude F is applied. Neglect the weight of the board itself. If the system is in equilibrium, what is F?

2007-11-01 10:03:15 · 1 answers · asked by Anonymous

a river flows south at 3m/s and is 50 m wide. An intrepid beaver sets out from west shore, aiming himself directly east. He swims with velocity relative to the water of 2m/s, east.
how long to cross stream
velocity
how far downstream
how long to cross river when dam is broke and velocity is 25m/s

2007-11-01 09:54:35 · 2 answers · asked by Don 1

if you are swinging a string with washers tied to the end 2.0 meters off the floor with a motion that has a radius of 1.0 meters and a period of 1.5 econds, how far would the washers fly if the string broke?

2007-11-01 09:40:41 · 2 answers · asked by brubabe 5

think of newtons laws...
1st. an object in motion stays in motion unless a net force is acted upon it.
2nd.F=MA
3rd. For every action there is an equal an opposite reaction
Think inertia...

2007-11-01 09:34:47 · 1 answers · asked by Anonymous

Hi, I am having a really hard time with these problems. The static, kinetic, and coefficient are giving me the hard time. Someone help me plz! Thanks.

1. At a wedding receoption, you notice a small boy who looks like his mass is about 25kg running part way across the dance floor, then slidding on his knees until he stops. IF the kinetic coefficient of friction between the boy's pants and the floor is 0.15, what is the frictional force acting on him as he slides?

2. If you use a horizontal force of 30 N to slide a 12kg wooden crate across the floor at a constant velocity, what is the coefficient of kinetic friction between the crate and the floor?

3. A 225 kg crate is pushed horizontally w/ a force of 710N. If the coefficient of fricition is 0.20, calculate the accleration of the crate.

4. A force of 40.0 N accelerates a 5.0kg block at 6.0 m/s squared along a horizontal surface. How large is the frictional force and what is the coefficient of friction.

2007-11-01 09:31:49 · 1 answers · asked by Karl 1

a teacher is loaded in a tank and fire at 53.1 degree angle hint (3,4,5) with speed of 100m/s. in flight he rises and fall back to a level 50 m below the height from which he started. ignore air resistance

2007-11-01 09:28:18 · 2 answers · asked by Don 1

A 58.2 kg sign is suspended by two wires, as the drawing shows. Find the tension in wire 1 and in wire 2.
http://www.webassign.net/CJ/4-58alt.gif

2007-11-01 09:18:05 · 3 answers · asked by Johnny Carson 2

2007-11-01 09:04:52 · 5 answers · asked by Alexander 6

A 1310 kg car drives up a hill that is 16.5 m high. During the drive, two nonconservative forces do work on the car: (i) the force of friction, and (ii) the force generated by the car's engine. The work done by friction is -3.21 x 10^5 J; the work done by the engine is +6.33 x 10^5 J. Find the change in the car's kinetic energy from the bottom of the hill to the top of the hill.



Thanks so much for your help!!! God Bless!!

2007-11-01 08:56:51 · 3 answers · asked by PaNaSoNiCeDgE 1

the formula for this problem is J=FavgT i just don't know how to plug in the numbers and units THANKS!

2007-11-01 08:48:30 · 2 answers · asked by Anonymous

Physics Homework Help, Best answer will be given.?
In the Netherlands a dike, holding back the sea from a town below sea level, springs a leak 3.8 m below the water surface. If the area of the hole in the dike is 1.2 cm2, what force must the Dutch boy exert to save the town? (For the density of sea water use the value 1025 kg/m3.)

Have tried a few things but none worked, please help!

2007-11-01 08:37:23 · 1 answers · asked by burning_ice_73 2