Physics Force & Laws Of Motion Level: Misc Level
A 70 kg man in a 5.0 kg chair tills back so that all the weight is balanced on tow legs of the chair. Assume that each leg makes contact with the floor over a circular area with a radius of 1.0 cm. Find the pressure exerted on the floor by each leg.
Physics Waves And Oscillations Level: Misc Level
An ultrasonic beam used in scanning body tissues has a frequency of 1.2 M H z. If the speed of sound in a particular tissue is 1540 m /s and the limit of resolution is equal to one wavelength, what is the size of the smallest detail that can be resolved?
Physics Waves And Oscillations Level: Misc Level
A visitor to a lighthouse wishes to determine the height of the tower. She ties a pool of thread to a small rock a simple pendulum, whieh she hangs down the center of a spiral staircase. The period of oscillation is 9.40 s. what is the height of the tower?
Physics Waves And Oscillations Level: Misc Level
When four people with a combined mass of 350 kg sit down in a car, they find that the car drops 0.80 cm lower on its springs. Then they get out of the car and bounce it up and down. What is the frequency of the car's vibration if its mass (empty) is 1650 kg?
Physics Vectors Level: Misc Level
A football player runs the pattern given in the drawing by the three direction vectors A, B, C, The magnitudes of these vectors A =5.00 m, B =15 ms C =18.0 m. Using he component method, find the magnitude and direction of resultant vector.
Physics Force & Laws Of Motion Level: Misc Level
Two forces are applied to a tree stump to pull it out of the ground. Force has a magnitude of 2240 N and points 34.0 % south of east, while force F B has a magnitude at 3160 N and points due south. Using the component method, find the magnitude s direction of the resultant force that is applied to the stump. Specify the direction with respect to due east.
Physics Force & Laws Of Motion Level: Misc Level
Two ropes are attached to a heavy box to pull it along the floor. One ropes applies a force of 475 N in a direction due west: the other applies a force of 315 N in a direction due south. a) How much force should be applied by a single rope, and b) in what direction (relative to due west), if it is to accomplish the same effect as the force added together?
Physics Current Electricity Level: Misc Level
Calculate the currents through all the resistors in the diagram.
Physics Current Electricity Level: Misc Level
Apply Kirchhoff s rules to the following circuit and (a) the current in each resistor and (b)the rate at which energy is being delivered to the 25 resistor.
Physics Waves And Oscillations Level: Misc Level
How many beats are heard when two organ pipes, each open at both ends, are sounded together if one pipe is 44 cm long and the other is 65 cm long?
Physics Waves And Oscillations Level: Misc Level
Horseshoe bats use the Doppler effect to determine their location. A horseshoe bat flies toward a wall at a speed of 12 m/s while emitting a sound of frequency 35 kHz. What is the beat frequency between the emission frequency and the echo?
Physics Waves And Oscillations Level: Misc Level
A supersonic plane moves at speed v plane, the speed of sound is v sound. If the conical shock wave makes an angle with the direction of motion of the plane (the figure below), we find that sin =v sound /v plane. Suppose a plane is flying at supersonic speed at an elevation where the speed of sound is 329 m/s. The shock wave cone form with an angle =21.0% with the direction of motion of the plane.
(a) What is the Mach number for this plane?
(b)How fast is the plane traveling? m/s
Physics Waves And Oscillations Level: Misc Level
An organ pipe that is open at both ends has a fundamental frequency of 385 Hz at 0 %C. What is the fundamental frequency for this pipe at 20.0%C?
Physics Waves And Oscillations Level: Misc Level
(a) What is the pressure amplitude of a sound wave with an intensity level of 120.5 dB in air?
(b) What force does this exert on eardrum of area 0.580 10-4 m?
Physics Waves And Oscillations Level: Misc Level
A sound wave with an intensity level of 80.4 dB is incident on an eardrum of area 0.600 10-4 m2. How much energy is absorbed by the eardrum in 3.0 minutes?
