Kyhry T

How many electrons have been removed from a positively charged electroscope if it has a net charge of 7.5 x 10-11 C?

What is the charge on an electroscope that has an excess of 4.8 x 1010 electrons?

Please help me with finding Sound "I have quiz tomorrow.?

Assume that the speed of sound in air is 343 m/s, at 20C, unless otherwise noted.

2. You are listening to an outdoor concert on a day when the temperature is 0C. The sound of a wavelength of .490 m is emitted by a flute on the stage 125 m from where you are standing.

a) What is the time elapsed before you hear the sound emitted from the stage?

b) What is the frequency of the sound?

3. The engine of a jet plane taking off produces a sound level of 140 dB, and the sound wave has a pressure amplitude of 200 Pa. A baggage handler working next to a jet plane that is taking off is waring specially designed hearing protectors that reduce the sound level entering his ear by 40 dB. What is the pressure amplitude of the sound wave entering his ear?

**Please show your work, so I can understand how to do this in the future.

Please answer 1 or both...

Assume that the speed of sound in air is 34 m/s at 20 C, unless otherwise noted.

1. The sound a mosquito makes is produced when it beats its wing at the average frequency of 620 wing beats per second. What is the wavelength of the sound waves produced by the mosquito

The pulse echo technique is used in diagnostic medical imaging. A short ultrasound pulse is emitted from the device, and echoes are produced when the pulse is reflected at a tissue interface. The echo signals are received back at the device and then analyzed to build up an image of the organ. The speed of the sound in soft tissue is 1540 m/s. If an echo is received 58.2x10^-6s after the pulse was emitted, how far is the tissue interface from the ultrasound device?

A neg charge of 2.0x10^-8 C experiences a force of .060 N to the right in an electric field. What are the field's magnitude and direction at that locations?

What is the magnitude of the electric field strength at a position that is 1.2m from a point charge of 4.2x10^-6

PLEASE HELP ME!!!

Sphere A is located at the orgin and has a charge of +2.0 x 10^-6 C. Sphere B is located at +.60 m on the x-axis and has a charge of -3.6 x10^-6C. Sphere C is located at +.80m on the x-axis and has a charge of +4.0x1-^-6C. Determine the net force on sphere A.

Determine the net force on sphere B in the prvious problem.

Rocio strikes a .058 kg golf ball with a force of 272 N and gives it a velocity of 62.0 m/s. How long was Rocio's club in contact with the ball?

A 0.145 kg baseball is pitched at 42 m/s. The batter hits it horizontally to the pitcher at 58 m/s

Find the change in momentum of the ball.

If the ball and bat are in contact for 4.6 x 10^-4 s, what is the average force during contact?

A force of 186 N acts on a 7.3 kg bowling ball for .40 s. What is the bowling ball's change in momentum. What is its change in velocity?

In a ballistics test at the police department, Officer Rios fires a 6.0 kg bullet at 350 m/s into a container that stops it in 1.8 ms. What is the average force that stops the bullet?

Please use significant digits, and show your work so I can understand how to do these types of problem in the future.

I need help with these physics problems. I have no idea how to do them...?

Rocio strikes a .058 kg golf ball with a force of 272 N and gives it a velocity of 62.0 m/s. How long was Rocio's club in contact with the ball?

A 0.145 kg baseball is pitched at 42 m/s. The batter hits it horizontally to the pitcher at 58 m/s

Find the change in momentum of the ball.

If the ball and bat are in contact for 4.6 x 10^-4 s, what is the average force during contact?

A force of 186 N acts on a 7.3 kg bowling ball for .40 s. What is the bowling ball's change in momentum. What is its change in velocity?

In a ballistics test at the police department, Officer Rios fires a 6.0 kg bullet at 350 m/s into a container that stops it in 1.8 ms. What is the average force that stops the bullet?

Please use significant digits, and show your work so I can understand how to do these types of problem in the future.

Rocio strikes a .058 kg golf ball with a force of 272 N and gives it a velocity of 62.0 m/s. How long was Rocio's club in contact with the ball?

A 0.145 kg baseball is pitched at 42 m/s. The batter hits it horizontally to the pitcher at 58 m/s

Find the change in momentum of the ball.

If the ball and bat are in contact for 4.6 x 10^-4 s, what is the average force during contact?

A force of 186 N acts on a 7.3 kg bowling ball for .40 s. What is the bowling ball's change in momentum. What is its change in velocity?

In a ballistics test at the police department, Officer Rios fires a 6.0 kg bullet at 350 m/s into a container that stops it in 1.8 ms. What is the average force that stops the bullet?

Please use significant digits, and show your work so I can understand how to do these types of problem in the future.

A 5500-kg freight truck accelerates from 4.2 m/s to 7.8 m/s in 15.0 s by the application of a constant force.

a)What change in momentum occurs?

b) How large of a force is exerted?

A .24 kg volleyball approaches Tina with a velocity of 3.8 m/s. Tina bumps the ball, giving it a speed of 2.4 m/s but in the opposite direction. What average force did she apply if the interaction time between her hands and the ball was .025 s.

A hockey player makes a slap shot, exerting a constant force of 30.0N on the hockey puck for .16s. What is the magnitude of the impulse given to the puck?

***Please use significant digits, and show your work so I can understand how to do these types of problem in the future.

Six years ago a house was purchased for $89, 000. This year it was appraised at $125,000. Find the average rate of change and use it to determine the value for 9 years.

On a typical summer evening the temperature was 90 degress F at 7 PM. At 8 AM the next morning the temperature was degress 70.5 F. What is the average rate of change in temperature.

Are these lines perpendicular, parallel, or neither.

Line 1: through (2,4) and (-1, -5)

Line 2: Through (0, -2) and (-3, 7)

Line 1: through (-3,5) and (-6,1)

Line 2: through (-2, -5) and (4, -8)

Please show your work so I can understand how to do these problems for the near future. Thanks!!

After dropping from a height of 1.50 m onto a concrete floor, a 50.0-g ball revounds to a height of .90 m.

a) FInd the impulse acting on the ball as it dropped.

b) Find the impulse acting on the ball as it rebounds

c) Find the impulse on the ball while it was in contact with the floor.

Thanks, I appreciate it. Please show your work, So I can understand how to do this in the future...Also use Significant Digits when you get your final answer- this will help me better understand significant digits.

An ice-skater with a mass of 75.0 kg pushes of against a second skater with a mass of 42.0 kg. Both skaters are initially at rest. After the push, the larger skater moves off with a speed of .75 m/s eastward. What is the velocity (magnitude and direction) of the smaller skater after the push?

Suppose a 55.0 kg ice-skater, who was initially at rest, fires a 2.50 kg gun. The 0.045 kg bullet leaves the gun at a velocity of 565.0 m/s. What is the velocity of the ice-skater after she fires the gun.

Please use significant digits w. your final answer. Thanks in advance for helping me :)

You can stand on the pedal of a bicycle. If you have a mass of 65 kg, the pedal makes an angle of 35 degress above the horizontal, and the pedal is 18 cm from the center of the chain ring, how much torque would you exert....

(this is the real question)******

if the pedal in problem 14 is horizontal, how much torque would you exert? How much torque would you exert when the pedal is vertical?

*I included the first question for background info - which seems to be necessary to answer the 2nd question. I get the first one, but not the second one...CAN SOME1 PLEASE HELP ME, I HAVE NO IDEA ON HOW TO DO THIS!!!

Thanks in advance:)

*If a torque of 55.0 N m is required and the largest force that can be exerted by you is 135N, what is the length of the lever arm that must be used?

Please help me solve this problem...Show you work, so I can understand how to do similar problems. Anything would help!!!!

Thanks. :)

A rectangular room has an area of 400 square foot. The length is 7 feet less than twice the width. Find the dimensions of the room?

A rectangular rug is to fit in a room so that a border of uniform with is left on all four sides. If the room is 12 feet by 14 feet and the area is 80 square feet, how wide will the border be?

a. √540

b. ∛6(4∛12 + 5∛9)

c. ∛-6750

d. ∜8/9a^3

e. (√18 + 2√3)^2

Please show your work, so I can understand this better, and prepare myself better for my quiz tomorrow...thanks, :)

Help me simplify radicals??

√5/12

√2/3 x √3/4

√10/3 x √9/5

√5/6 x √5/2

-6√9x + 3√64x - √50x

Help me simplify radicals?

√3/7

√5/12

√9/20

√18/5

3/8x + .13x - 6 = 1/12x + 13/40

Help me solve this complicated math problem..?

3(x-8)-5x+6=-4-(4-3x)

First I got: x=3.4, then I got x=-2

Then, help me solve 4[5x-(3-8x)+6x] = -x-5

I gt x= -1/13

Then help me solve this one: (most hard one for me)

7(2x-5)+15x=5(9x-7)+87x

I got x=no solution, but Im pos. that is wrong.