Physics Waves And Oscillations Level: High School
Interference
A pair of speakers separated by .7 m are driven by the same oscillator at a frequency of 690 Hz . An observer originally positioned at one of the speakers begins to walk along a line perpendicular to the line joining the speakers , how far will the observer be from the speaker when the first relative minimum is detected in the intensity ?
Physics Properties Of Matter Level: High School
Archimedes’s Principle
A spherical balloon is made from a material whose mass is 3.00 kg . The thickness of the material is negligible compared to the 1.2 m radius of the balloon . The balloon is filled with helium (He) at a temperature of 303 K and just floats in air , neither rising not falling . The density of the surrounding air is 1.19 kg/m^3 .Find the absolute pressure of the helium gas .
Physics Properties Of Matter Level: High School
Boyle's Law
A gas fills the right portion of a horizontal cylinder whose radius is 4.00 cm . The initial pressure of the gas is 1.01 x 10^5 Pa . A frictionless movable piston separates the gas from the left portion of the cylinder ,which is evacuated and contains an ideal spring , as the drawing at ‘click here’ shows . The piston is initially held in place by a pin . The spring is initially unstrained , and the length of the gas filled portion is 21.0 cm. When the pin is removed and the gas is allowed to expand , the length of the gas-filled chamber doubles . The initial and final temperature are equal . Determine the spring constant of the spring .
Physics Properties Of Matter Level: High School
What is the density of nitrogen gas (molecular mass = 28 u) at a pressure of 2.4 atmospheres and a temperature of 320 K ?
Physics Heat & Thermodynamics Level: High School
A person eats a container of yogurt . The Nutritional Facts label states that it contains 195 Calories ( 1 calorie = 4186 J)What mass of perspiration would one have to lose to get rid of this energy ? At body temperature ,the latent heat of vaporization of water is 2.42 x 10^6 J/kg .
Physics Waves And Oscillations Level: High School
Simple Harmonic Motion
A 5.00 kg object on a horizontal frictionless surface is attached to a spring with k = 1000 N/m . The object is displaced from equilibrium 50.0 cm horizontally and given an initial velocity of 10.0 m/s back toward the equilibrium position . What are (a) the motions frequency , (b) the initial potential energy of the block-spring system, (c) the initial kinetic energy , and (d) amplitude ?
Physics Waves And Oscillations Level: High School
Simple Harmonic Motion
An oscillator consists of a block attached to a spring (K = 400 N/m). At some point t, the position (measured from the system’s equilibrium location), velocity, and acceleration of the block are x = 0.100 m, v = -13.6 m/s , and a = -123 m/s^2 . Calculate ,a) the frequency of oscillation .
b) the mass of the block .
c) the amplitude of the motion .
Physics Waves And Oscillations Level: High School
Simple Harmonic Motion
The velocity v(t) of a particle undergoing Simple harmonic motion is graphed in figure at “click here” . Is the particle momentarily stationary , headed toward –xm , or headed toward +xm at (a) Point A on the graph and point B ? Is the particle at –xm , at +xm , at 0, between –xm and 0,or between 0 and + xm when its velocity is represented by (c) point A and (d) point B ? Is the speed of the particle increasing or decreasing at (e) point A and (f) point B ?
Physics Force & Laws Of Motion Level: High School
Impulse
A 300 g ball with a speed v of 6.0 m/s strikes a wall at an angle theta = of 30 degree and then rebounds with the same speed and the angle , it is in contact with the wall for 10 ms . In unit-vector notation , what area) the impulse on the ball from the wall ?
b) the average force on the wall from the ball ?
Physics Force & Laws Of Motion Level: High School
Impulse
It is well known that bullets and other missiles fired at superman simply bounce off his chest . Suppose a gangster says superman’s chest with 3 g bullet at the rate of 100 bullets/min, and the speed of each bullet is 500 m/s . Suppose too that the bullets rebound straight back with no change in speed . What is the magnitude of the average force on superman’s chest from the stream of bullets ?
Physics Force & Laws Of Motion Level: High School
Conservation of Momentum
A shell is shot with an initial velocity v0 of 20 m/s , at an angle of (theta) = 60 degrees with the horizontal . At the top of the trajectory , the shell explodes into two fragments of equal mass . One fragment , whose speed immediately after the explosion is zero , falls vertically , How far from the gun does the other fragment land , assuming that the terrain is level and that air drag is negligible ?
Physics Rotational Mechanics Level: High School
Centre of Mass
In the ammonia (NH3) molecule , three hydrogen atoms form an equilateral triangle , with the center of the triangle at distance d = 9.40 x 10^-11 m from each hydrogen atom . Nitrogen atom is at the apex of a pyramid , with the three hydrogen atoms forming the base . The nitrogen to hydrogen atomic mass ratio is 13.9 , and the nitrogen to hydrogen distance is L = 10.14 x 10^-11 m . What are the x and y coordinates of the molecule’s center of mass ?
Physics Kinematics Level: High School
First Equation of Motion
Time is 3.6 sec distance is 20 meters initial velocity is 0 What is the final velocity ?
Physics Rotational Mechanics Level: High School
Rotational Equilibrium
The automatic flag raising system on a horizontal flagpole attached to the vertical outside wall of a tall building has become stuck . The management of the building wants to send a person crawling out along the flagpole to fix the problem . Because of your physics knowledge, you have been asked to consult with a group to decide whether or not this is possible . You are all to aware that no one could survive the 250 foot fall from the flagpole to the ground . The flagpole is a 120 lb steel I-beam which is very strong and rigid . One side of the flagpole is attached to the wall of the building by hinge so that it can rotate vertically . Nine feet away , the other end of the flagpole is attached to a strong , lightweight cable . The cable goes up from the flagpole at an angle of 30 degree unit it reaches the building where it is bolted to the wall . The mechanic who will climb out on the flagpole weighs 150 lbs including equipment . From the specification of the building construction , both the bolt attached the cable to the building and the hinge have been tested to hold a force of 500 lbs . Your boss has decided that the worse case is when the mechanic is at the far end of the flagpole , nine feet from the building .
Physics Work,Power & Energy Level: High School
Inelastic Collision
A cart of mass m = 0.20 kg moving at velocity v = 3.0 m/s collides inelastically with an initially stationary cart of mass 0.40 kg . If the carts stick together , what is their combined velocity immediately after the collision ?
In the absence of frictional forces , draw a diagram labeling the force acting on each cart at the moment of collision . Are these internal or external forces ?