Friday

April 18, 2014

April 18, 2014

Total # Posts: 19

**physics**

A 25-g lead bullet is shot with a speed of 240 m/s into a wooden wall. Assuming that 70% of the kinetic energy is absorbed by the bullet as heat (and 30% by the wall), what is the final temperature of the bullet? (Assume the bullet is initially at room temperature of 20°C.

**physics**

Suppose 300 g of water at 20°C is poured over a 50-g cube of ice with a temperature of -6°C. If all the ice melts, what is the final temperature of the water? If all of the ice does not melt, how much ice remains when the water–ice mixture reaches equilibrium?

**physics**

The thermal conductivity of fiberglass batting, which is 9.4 in thick, is 8.6 10-6 BTU/(ft °F s). What is the R value (in ft2 °F h/BTU)?

**physics**

The label on a soft drink states that 15 fl. oz (444 g) provides 170 kcal. The drink is cooled to 11.0°C before it is consumed. It then reaches body temperature of 37°C. Find the net energy content of the drink. (Hint: You can treat the soft drink as being identical to...

**physics**

A 5-g ice cube at ?4°C is dropped into 60 g of water at 40°C. (For the following problems, use the specific heats in this table and the numerical data found in this table.) (a) After enough time has passed to allow the ice cube and water to come into equilibrium, what ...

**physics**

A wave on a string has a wave function given by y(x, t) = (0.0210 m)sin[(6.91 m^−1)x + (2.38 s^−1)t . (a) What is the amplitude of the wave? (b) What is the period of the wave? (c) What is the wavelength of the wave? (d) What is the speed of the wave?

**physics**

Suppose the slope of a beach underneath the ocean is 21 cm of dropoff for every 1.2 m of horizontal distance. A wave is moving inland, slowing down as it enters shallower water. What is its acceleration when it is 16 m from the shoreline? (Let the +x direction be towards the s...

**physics**

calculated**

**physics**

thanks! may I ask how you calculate the fundamental wavelength or is it a constant?

**physics**

thanks! but whats ñ

**physics**

The tension in a 2.8-m-long, 1.2-cm-diameter steel cable (ρ = 7800 kg/m3) is 825 N. What is the fundamental frequency of vibration of the cable?

**physics**

A 46-cm-long wire with a mass of 10.5 g is under a tension of 52.0 N. Both ends of the wire are held rigidly while it is plucked. (a) What is the speed of the waves on the wire?

**physics**

The Moon can be considered to be a sphere with uniform density with mass MM and radius RM. At the (exact) center of the Moon, the gravitational force on a mass m due to the mass of the Moon is? I know the answer is zero but want to know why using gauss' law

**physics**

A comet orbits the Sun with a period of 71.8 yr. (a) Find the semimajor axis of the orbit of the comet in astronomical units (1 AU is equal to the semimajor axis of the Earth's orbit). (b) If the comet is 0.50 AU from the Sun at perihelion, what is its maximum distance fro...

**physics**

A 3.3-kg ball of clay with a speed of 14 m/s is thrown against a wall and sticks to the wall. What is the magnitude of the impulse exerted on the ball?

**physics**

A 58-kg astronaut inside a 9-m-long space capsule of mass 550 kg is floating weightlessly on one end of the capsule. He kicks off the wall at a velocity of 3.6 m/s toward the other end of the capsule. How long does it take the astronaut to reach the far wall?

**physics**

A satellite with a mass of 260 kg approaches a large planet at a speed vi,1 = 13.1 km/s. The planet is moving at a speed vi,2 = 10.2 km/s in the opposite direction. The satellite partially orbits the planet and then moves away from the planet in a direction opposite to its ori...

**physics**

A cannonball of mass 6.09 kg is shot from a cannon at an angle of 47.18° relative to the horizontal and with an initial speed of 48.90 m/s. As the cannonball reaches the highest point of its trajectory, what is the gain in its potential energy relative to the point from wh...

**chemistry**

Compute the empty cells. Consider PTN conditions (For SO2, NO, NO2, and C5H8 express the mass concentration in Kg S m-3, Kg N m-3, Kg C m-3, respectively). Gas/Unit mg m-3 molecules ppm ppb cm-3 % O3 180 SO2 4.0 x 1015 NO 60 NO2 10 NOx CO 30 C5H8 6

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