Physics Answers

A V-canyon supports a 100-ft high, constant-angle (120°) arch dam. If the canyon is 60 ft wide at the top and the design freeboard is 6 ft (ie., the water level is 6 ft below the top of the dam), determine the abutment reactions at dam heights of 25, 50, and 75 ft above the bottom of the canyon.

Find the change in volume of 30 L of a fluid when subjected to a

pressure increase of 2.0 MPa. The bulk modulus of elasticity of the

fluid is 2.24 GPa.

A 10.00 CM tall light bulb is placed at a distance of 90.0 CM from a concave mirror

having a focal length of 21 CM Determine the image distance and the image size

A ball of mass m1=4kg and a block of mass m2=10kg

are attached by a lightweight cord that passes

over a frictionless pulley of negligible mass, as in figure below. The block lies on a frictionless incline of

angle θ=48 degrees. Find the magnitude of the acceleration of the two objects and the tension in the cord.

What is matter made of?

At point A, 3.0 m from a small source of sound that is emitting uniformly in all directions, the sound intensity level is 53 dB. (a) What is the intensity of the sound at A? (b) How far from the source must you go so that the intensity is one-fourth of what it was at A? (c) How far must you go so that the sound intensity level is one-fourth of what it was at A

Sound is detected when a sound wave causes the tympanic membrane (the eardrum) to vibrate. Typically, the diameter of this membrane is about 8.4 mm in humans. (a) How much energy is delivered to the eardrum each second when someone whispers (20 dB) a secret in your ear? (b) To comprehend how sensitive the ear is to very small amounts of energy, calculate how fast a typical 2.0-mg mosquito would have to fly (in mm/s) to have this amount of kinetic energy

In a sinusoidal wave of moderate loudness, the maximum pressure variations are about above and below atmospheric pressure. Find the corresponding maximum displacement if the frequency is 10,000 Hz. In air at normal atmospheric pressure and density, the speed of sound is 344 m/s and the bulk modulus is .

Standing sound waves are produced in a pipe that is 1.20 m long. For the fundamental and first two overtones, determine the locations along the pipe (measured from the left end) of the displacement nodes and the pressure nodes if (a) the pipe is open at both ends and (b) the pipe is closed at the left end and open at the right end

A piano tuner stretches a steel piano wire with a tension of 800 N. The steel wire is 0.400 m long and has a mass of 3.00 g. What is the frequency of its fundamental mode of vibration? What is the number of the highest harmonic that could be heard by a person who is capable of hearing frequencies up to 10,000 Hz?