?

ill be doing bows and bow holders tutus for little girls and other things but i can not come up with a name i thought about spelling boutique bowtique but i cant think of a catchy name =/

A bucket filled with water has a mass of 23 kg and is attached to a rope, which in turn, is wound around a 0.050-m radius cylinder at the top of a well. What torque does the weight of water and bucket produce on the cylinder if the cylinder is not permitted to rotate? (g = 9.8 m/s2)

Alex throws a 0.15-kg rubber ball down onto the floor. The ball’s speed just before impact is 6.5 m/s, and just after is 3.5 m/s. What is the change in the magnitude of the ball’s momentum?

a. 0.09 kg×m/s

b. 1.5 kg×m/s

c. 4.3 kg×m/s

d. 126 kg×m/s

Carbon dioxide forms into a solid (dry ice) at approximately -157°F. What temperature in degrees Celsius does this correspond to?

3 A potential difference of 90 mV exists between the inner and outer surfaces of a cell membrane. The inner surface is negative relative to the outer surface. How much work is required to eject a positive sodium ion (Na+: q = 1.60 x 10-19 C) from the interior of the cell?

b. 6.1 x 10-15 J

c. 9.2 x 10-20 J

d. 0 J

e. 1.4 x 10-20 J

i was thinking e on this one??

2. Suppose your waffle iron is rated at 1.00 kW when connected to a 1.20 x 102 V source. (a) What current does the waffle iron carry? (b) What is its resistance?

a. 8.33 A, 14.4 Ohms

b. 8.33 A, 10.8 Ohms

c. 5.93 A, 14.4 Ohms

d. 5.93 A, 10.8 Ohms

and i was thinking c on this one but i wanted to double check thanks!!!

1. A 7.5-nC (n = 10-9) is located 1.8 m from a 4.2-nC charge. Find the magnitude of the electric force that one charge exerts on the other. Is the force attractive or repulsive

a. 8.7 x 10-4 N, attractive

b. 8.7 x 10-4 N, repulsive

c. 5.3 x 10-4 N, attractive

d. 5.3 x 10-4 N, repulsive

im thinking its b but i wanted to double check =)

here is my second one

2. If a current of 80.0 mA (m=10-3) runs through a metal wire, how many electrons flow past a given section of the wire in 10.0 min?

a. 3.00 x 1020 electrons

b. 8.00 x 1010 electrons

c. 4.00 x 1030 electrons

d. 7.00 x 105 electrons

im thinking this one is c but once again not sure =)

If a human ear canal can be thought of as resembling an organ pipe, closed at one end, which resonates at a fundamental frequency of 2925 Hz, what is the length of the canal? Use normal body temperature 37°C for your determination of the speed of sound in the canal.

____cm

The human ear canal is about 3.0 cm long. If it is regarded as a tube open at one end and closed at the eardrum, what is the fundamental frequency around which we would expect hearing to be most sensitive? (Take the speed of sound to be 350 m/s.)

____ kHz

A commuter train passes a passenger platform at a constant speed of 38.0 m/s. The train horn is sounded at its characteristic frequency of 320 Hz.

(a) What overall change in frequency is detected by a person on the platform as the train moves from approaching to receding?

____ Hz

(b) What wavelength is detected by a person on the platform as the train approaches?

_____ m

An airplane traveling at v = 146 m/s emits a sound of frequency 6.00 kHz. At what frequency does a stationary listener hear the sound during each of the following times? (Use 344 m/s as the speed of sound.)

(a) as the plane approaches

____ kHz

(b) after it passes

____kHz

If a human ear canal can be thought of as resembling an organ pipe, closed at one end, which resonates at a fundamental frequency of 2925 Hz, what is the length of the canal? Use normal body temperature 37°C for your determination of the speed of sound in the canal.

____cm

The human ear canal is about 3.0 cm long. If it is regarded as a tube open at one end and closed at the eardrum, what is the fundamental frequency around which we would expect hearing to be most sensitive? (Take the speed of sound to be 350 m/s.)

____ kHz

An airplane traveling at v = 146 m/s emits a sound of frequency 6.00 kHz. At what frequency does a stationary listener hear the sound during each of the following times? (Use 344 m/s as the speed of sound.)

(a) as the plane approaches

____ kHz

(b) after it passes

____kHz

The windpipe of a typical whooping crane is about 4.3 ft long. What is the lowest resonant frequency of this pipe, assuming that it is closed at one end? Assume a temperature of 34°C.

___ Hz

The distance between two successive minima of a transverse wave is 2.40 m. Five crests of the wave pass a given point along the direction of travel every 12.9 s.

(a) Find the frequency of the wave.

____ Hz

(b) Find the wave speed.

_____m/s

A commuter train passes a passenger platform at a constant speed of 38.0 m/s. The train horn is sounded at its characteristic frequency of 320 Hz.

(a) What overall change in frequency is detected by a person on the platform as the train moves from approaching to receding?

____Hz

(b) What wavelength is detected by a person on the platform as the train approaches?

_____ m

The range of human hearing extends from approximately 20 Hz to 20000 Hz. Find the wavelengths of these extremes at a temperature of 28°C. 20 Hz 1 m

20000 Hz ______ m

The coldest recorded temperature of air on Earth, -128.6°F, occurred on July 21, 1983, at Vostok, a Russian station in Antarctica. What is the speed of sound in air at this temperature?

____m/s

A dolphin located in sea water at a temperature of 25°C emits a sound directed toward the bottom of the ocean 180 m below. How much time passes before it hears an echo?

______ s

What affect will doubling the component of the applied force PERPENDICULAR to the wrench without changing the component parallel to the wrench have on the torque???

The distance between two successive minima of a transverse wave is 2.40 m. Five crests of the wave pass a given point along the direction of travel every 12.9 s.

(a) Find the frequency of the wave.

___ Hz

(b) Find the wave speed.

___ m/s

A bat can detect small objects, such as an insect, whose size is approximately equal to one wavelength of the sound the bat makes. If bats emit a chirp at a frequency of 59.0 kHz, and if the speed of sound in air is 340 m/s, what is the smallest insect a bat can detect?

___mm

The coldest recorded temperature of air on Earth, -128.6°F, occurred on July 21, 1983, at Vostok, a Russian station in Antarctica. What is the speed of sound in air at this temperature?

___ m/s

Can you help me in physics?

A 49 kg woman cheats on her diet and eats a 576 Calorie (540 kcal) jelly donut for breakfast.

(a) How many joules of energy are the equivalent of one jelly doughnut?

___ J

(b) How many stairs must the woman climb to perform an amount of mechanical work equivalent to the food energy in one jelly doughnut? Assume the height of a single stair is 15 cm.

___stairs

(c) If the human body is only 20% efficient in converting chemical energy to mechanical energy, how many stairs must the woman climb to work off her breakfast?

____ stairs

A 94 g cube of ice at 0°C is dropped into 1.0 kg of water that was originally at 90°C. What is the final temperature of the water after the ice has melted?

____°C

How much energy is required to change a 60 g ice cube from ice at -30°C to steam at 105°C?___ J

A 49 kg woman cheats on her diet and eats a 576 Calorie (540 kcal) jelly donut for breakfast.

(a) How many joules of energy are the equivalent of one jelly doughnut?

___ J

(b) How many stairs must the woman climb to perform an amount of mechanical work equivalent to the food energy in one jelly doughnut? Assume the height of a single stair is 15 cm.

___stairs

(c) If the human body is only 20% efficient in converting chemical energy to mechanical energy, how many stairs must the woman climb to work off her breakfast?

____ stairs

A 94 g cube of ice at 0°C is dropped into 1.0 kg of water that was originally at 90°C. What is the final temperature of the water after the ice has melted?

____°C

How much energy is required to change a 60 g ice cube from ice at -30°C to steam at 105°C?___ J

According to the manual of a certain car, a maximum torque of magnitude 56.0 N · m should be applied when tightening the lug nuts on the vehicle. If you use a wrench of length 0.362 m and you apply the force at the end of the wrench at an angle of 75.00° with respect to a line going from the lug nut through the end of the handle, what is the magnitude of the maximum force you can exert on the handle without exceeding the recommendation?

____ N

Lake Erie contains roughly 4.00 multiplied by 1011 m3 of water.

(a) How much energy is required to raise the temperature of that volume of water from 9.0°C to 11.0°C?

__J

(b) How many years would it take to supply this amount of energy by using the 1200-MW exhaust energy of an electric power plant?

___ yr

A 85-g sample of silicon is at 20°C. If 650 cal of energy is transferred to the silicon, what is its final temperature?

____°C

A potter's wheel moves uniformly from rest to an angular speed of 0.21 rev/s in 25 s.

(a) Find its angular acceleration in radians per second per second.

___ rad/s2

A dentist's drill starts from rest. After 2.80 s of constant angular acceleration it turns at a rate of 2.9 104 rev/min.

(a) Find the drill's angular acceleration.

___rad/s2

(b) Determine the angle (in radians) through which the drill rotates during this period.

____ rad

Find the centripetal accelerations at each of the following points due to the rotation of Earth about its axis.

(a) a point on the Equator of Earth

___m/s2

(b) the North Pole

____ m/s2

(c) What two forces combine to create these centripetal accelerations?

A wheel has a radius of 4.7 m. How far (path length) does a point on the circumference travel if the wheel is rotated through angles of 30°, 30 rad, and 30 rev, respectively?

30° ___ m

30 rad ___ m

30 rev ___-m

The tires on a new compact car have a diameter of 2.0 ft and are warranted for 56,000 miles.

(a) Determine the angle (in radians) through which one of these tires will rotate during the warranty period.

___rad

(b) How many revolutions of the tire are equivalent to your answer in (a)?

___rev

An object has a kinetic energy of 297 J and a momentum of magnitude 22.8 kg·m/s. Find the speed and the mass of the object.

speed 26.05 m/s(this one is correct)

mass___ kg (this is not help on this 1 please)

A man claims he can safely hold on to a 10.3-kg child in a head-on collision with a relative speed of 139-mi/h lasting for 0.10 s as long as he has his seat belt on.

(a) Find the magnitude of the average force needed to hold onto the child.

____N

(b) Based on the result to part (a), is the man's claim valid?

___

A rifle with a weight of 30 N fires a 4.0 g bullet with a speed of 260 m/s.

(a) Find the recoil speed of the rifle.

___m/s

(b) If a 675 N man holds the rifle firmly against his shoulder, find the recoil speed of the man and rifle.

____ m/s