Physics Waves And Oscillations Level: High School
You have been captured by space aliens , and placed on board their ship in a windowless room . The spaceship takes off , and sometime later lands on what appears to be solid ground . You would like to know where you are . You have a strong suspicion about your captors , sine Zarkonian National Anthem was reverberating throughout the ship , and you figure it is likely that you have landed on either Zarkon or its moon Abba – although you might also have been brought back to Earth . Fortunately , along with your wristwatch , you have in your pocket a ruler , a 1.00 kg mass , and an ideal (massless) spring to which it can be hooked . (Doesn’t everybody have this kind of stuff in their pocket ? ) Unfortunately , you don’t know the sprig constant . However , you remember some physics , and you attach the mass to the spring and determine that the oscillation period for the mass+spring combination is 0.500 second .a) Is this enough information to figure out which planet/moon you are on ? why and why not ? Since the period is either not enough to figure out where you are , or for additional confirmation , you also determine that when the mass is suspended from the spring and hangs at equilibrium , the spring is stretched about 2.5 cm from its unstrained length .
b) Now you know for sure where you are ! Show how . Are you on Earth , Zarkon , or Abba
Physics Electromagnetic Waves Level: High School
Radio waves travel at the speed of light. The LORAN C navigation system (which has a transmitter near Searchlight , Nevada) operates on the relatively low radio frequency of 100 . KHz )a) What is the wavelength of the LORAN C signal ?
b) For comparison , what is the wavelength of the X-band (8.00 GHz = 8.00 x 10^9 Hz) telemetry signals which NASA uses to bring back picture of Saturn and its moons from the Cassini spacecraft ? ( The radio spectrum covers a wide range of wavelength)
Physics Rotational Mechanics Level: High School
Rotational Equilibrium
Suzee Cue , an intelligent physics student , needs to trim some tree branches which are extended out over the water . She invents the structure shown at “click here” to allow her to work at some distance from the end of a dock . She extends a 7.00 m long ,uniform board , having a mass of 100 kg , from the dock . On the dock end of the board , she has piled 250 . kg of sand . The center of gravity of the sand pile is 1.00 m inland from the end of the dock . Suzee has a mass of 50.0 kg .a) How far out over the water ,L , can Suzee work , before she gets wet . (ie , she and her apparatus tumble into the water) or can she work at the end of the board ?
b) If Suzee used this apparatus on Zarkon , would the limiting distance (L) be the same ? why or why not ?
Physics Work,Power & Energy Level: High School
In a kid’s dart gun , a spring is compressed and held in place by a latch until the gun is “fired” and the dart launched upward by the spring . Suppose the spring (ideal of course ) is compressed 0.0500 m when the gun is loaded , and the spring constant is 600.0 N/m .a) If the dart gun is aimed straight up , how will it shoot a 0.0150 kg dart ?
b) Suppose the dart gun spring also gave a spin to the dart . Would a spring dart go as a non-spinning dart ? Why or why not ?
Physics Rotational Mechanics Level: High School
Conservation of Energy
Consider the rotating platform of the above problem to be uniform disk of radius 2.50 m , with a total mass of 200.0 kg . The platform ultimately reaches a rotation rate of 5.00 rotations per second , at which point the acceleration stops and a 50.0 N force is applied to the rim of the platform by a brake mechanism which eventually brings the platform to a stop . The coefficient of kinetic friction between the brake pad and the platform is 0.800 .(Assume that the brake is the only cause of friction in the platform system and that the brake force is applied tangentially to the disk ) .a) What is the kinetic energy of the platform at its maximum rotation rate ?
b) What is the torque applied by the brake ?
c) How long does it take for the platform to stop rotating ?
Physics Rotational Mechanics Level: High School
Circular Motion
A box is sitting on a level rotating platform , 2.00 meters from the rotational axis of the platform . The coefficient of static friction between the box and the platform is 0.500 . An angular acceleration is applied to the platform . As the platform rotates faster and faster , the box will eventually slide off the platform .a) What is the speed of the box when it starts to slide ?
b) What is the rotation rate of the platform (in radians per second) when the box begins to slide ?
Physics Work,Power & Energy Level: High School
Your rich aunt sent you a few hundred dollars , with which you just bought a new Ferrari at Wynn Las Vegas . You are out tooling around the back roads of Nevada when you spot an escaped alien from Area 51 sauntering across the road ahead . To avoid the intergalactic incident that would occur had you run over this creature , you slam on the brakes , noting that you were going 150 miles per hour , Assume that the antilock brake system kicks in to keep the tires from skidding and that your supergrip tires have a static coefficient of friction of 0.95. Also , assume the mass of your new car is 1.30 x 10^3 kg , and the mass of the steel brake rotors is 4.00 kg each . (Remember , like most cars , Ferraris have four wheels , too )a) How fast were you going initially ,in meters per second ?
b) How far does it take for the car to stop ?
c) How much work was done by friction to slow down and stop your car ?
d) Was this work positive or negative ?
e) What was the initial kinetic energy of thecar and how does this relate to the frictional work ?
f) How much hotter did the brake rotors get as you stopped ,assuming no heat leaked from them ?
Physics Kinematics Level: High School
Projectile Motion
A projectile is fired horizontally (from the top of a very high cliff) with an initial speed of 60.0 m/s .a) What is the magnitude of the displacement of the projectile 3.00 seconds after it is fired ?
b) What is the speed of the projectile 3.00 seconds after it is fired ?
c) What is the acceleration of the projectile 3.00 seconds after it is fired ?
Physics Gravitation Level: High School
Where necessary use the Zarkon parameters given at the end of this problem .a) What would the radius of the Zarkon have to be so that the gravity at the surface of the Zarkon would be the same as the gravity at the surface of the Earth ?
b) Zarkon has a little moon (Abba) , which orbits Zarkon at a distance of 1.00 x 10^5 km from the planet’s center . How long is a month on Zarkon (in Zarkon days ) ? (Month =”month” = one revolution of a moon around its “parent” planet ) [The mass of Zarkon is 0.100 the mass of the Earth . A day on Zarkon is 10.0 Earth hours long .]
Physics Force & Laws Of Motion Level: High School
Conservation of Momentum
Greg Maddux (Las Vegas resident and pitcher for the Chicago Cube) has gone for a canoe ride on Lake Mead , taking along a baseball . Out on the water , when his canoe is motionless , Maddux stands up and throws a fastball over the stern (rear end) of the canoe . How fast will the canoe with Maddux stands up and throws a fastball over the stern (rear end) of the canoe . How fast will the canoe with Maddux in it be moving after he throws the fastball ? Take Maddux’s mass to be 90.0 kg , the canoe’s mass to be 50.0 kg , and the baseball’s mass to be 0.25 kg . Assume Maddux throws a 40.0 m/s fastball .
Physics Heat & Thermodynamics Level: High School
Thermal Expansion
How much taller is the Tower on a hot summer day ( 113 degree F) than on a cold (32 degree F) winter night ?
Physics Work,Power & Energy Level: High School
a) How much work must the Stratosphere elevator do to raise you and you friend (masses of 75.0 kg and 60.0 kg ) from the ground to the restaurant at the top ?
b) What is the minimum power rating for the elevator motor if the elevator must be able to carry 10 overweight conventioneers for 10 burly ex-XFL players ) of mass 150.0 kg each , along with the elevator mass of 1.50 x 10^3 kg , from the ground to the top in 60.0 seconds ?
Physics Kinematics Level: High School
Free Fall
You and your significant other have decided to celebrate with dinner at the top of the Tower . ( I recommend this , at sunset – but take more than a few $$ with you) After dinner , you decide to take some picture from the viewing at the top of the Tower . Unfortunately you drop your camera over the edge .a) How fast is your digital camera going just before its CCD sensor is smashed back to silicon powder when it hits the sidewalk at the base of the Tower ?
b) How long are you muttering under your breath between the time you drop the camera and hits the sidewalk ?
Physics Vectors Level: High School
A 5.50 kg penguin runs onto a huge sheet of frictionless Antarctic ice . At t = 0 and y = 0 with an initial velocity of 0.37 m/s along the positive x-axis . It slides while being pushed by the wind with a force of 0.53 N directed along the positive y-axis . Calculate the magnitude of the penguin’s velocity at t = 11.69 s .a) 1.19 m/s
b) 1.48 m/s
c) 1.85 m/s
d) 2.32 m/s
e) 2.89 m/s
Physics Waves And Oscillations Level: High School
Doppler Effect
John is listening to a horn . He knows the frequency of the horn is 300 Hz when both he and the horn are at rest .If he hears a pitch of 270 Hz ,there are clearly several possibilities .a) The distance between the John and the horn is decreasing with time .
b) Both can be moving and have the same speed .
c) Both can be moving but with the different speed .
d) Both can be moving in opposite direction
e) John is moving away from the horn at rest .
