  # anna

Members

15

## anna's Achievements 0

### Reputation

1. the Doppler effect is when the frequency of a sound wave becomes higher the closer you get to it and then the pitch lowers as it passes you again. when an ambulance is speeding down the street with its sirens on the pitch of the siren changes as it passes you. when it is coming towards you its pitch and frequency start to increase and then reach a maximum as the ambulance is right next to you. then as it drives passed you again the pitch and frequency of the siren lowers the farther and farther away it gets from you. the Doppler effect is the difference in frequency and pitch the siren makes as it passes you.
2. holding a conversation with someone involves a lot of physics. to create sound, when someone speaks their sound waves travel through a medium causing vibrations which is what creates the sound. the vibrations created by the sound wave passing through a medium are than picked up by my ear and cause my eardrum to vibrate which sends off neurons in my brain and that completes the process of hearing. this process is so fast that is seems instantaneous but it is actually a complex process that involves a lot of physics.
3. living so close to the lake we see water waves all the time. a water wave is longitudinal because the particles go with the direction of the water. the water is not actually moving when a wave is produced but the energy is. the energy in the water is pushed farther and farther inland until it reaches the shore but while the energy is causing the water to create a wave, the same water where the wave started is not what reaches the shore.
4. while we are headed into the summer, we can start to expect many thunderstorms soon. a thunderstorm is related to physics because of the speed of light and sound. while thunder and lightning occur at the same time, people always hear thunder after they see lightning. the velocity of the speed of sound is 331 m/s, this means that you can measure how far away from a storm you are by counting how many seconds there are from the time you see lightning to the time you hear thunder. for every second in between the thunder and lighting add 331 meters and you will be able to judge how many meters you are from the storm.
5. when hiking it is important to know what direction you are headed in. this sometimes can require a compass. a compass is a magnet that is aligned with the earths magnetic poles. the north direction of the earth is actually the south pole of its magnet. this means that the north pole of a compass will point north because it will be attracted to the south pole of the earths magnet. Having a compass always point north can help you if you get lost.
6. There is a lot of physics in race car driving because of centripetal force and acceleration. Also period and frequency. The centripetal force of a car going around a track is calculated by mass times velocity squared divided by the radius of the track. The centripetal acceleration if the car is calculated by velocity squared over radius. The frequency is revolutions per second so the number of times the car goes around the track divided by how long it takes him. The period is the opposite if frequency so it is the amount of time taken divided by the number of revolutions around the track.
7. The potential and kinetic energy in a roller coaster changes constantly. As a cart climbs up an incline it's potential energy is increases the higher it gets. At the top it's potential energy is calculated by mgh than when it falls it's kinetic energy increases. Kinetic energy is calculated by 1/2mv2. The total energy of the car is calculated by putting together the kinetic and potential energy.
8. When people go to the gym they are exserting energy which is caused by doing work. Work is the amount of force times the displacement there cant be any work done if nothing moves. Lifting weights is doing work because you are raising the weight over your head. The faster you do this the more power you are using. Power is work divided by the time it takes to complete the task.
9. Friction is reduced in the winter due to ice. Wheels on a car and even your shoes don't have as much traction on them during the winter because the ice decreases the amount of friction. This cause cars and people to slide which can be dangerous. Friction is due to gravity and the normal force on a person and also the surface that someone is on.
10. During a car crash momentum is used. Momentum is the mass times velocity of an object.a car that is really big like a truck that is going really fast is going to have a greater momentum than a car that is small and going slower. In a car crash the car with the smaller momentum will have more damage done to it because the force acting on it is greater.
11. while running there is a lot of physics involved. your inital veelocity is 0 if you are starting from rest and then you begin to acclerate at a constant or inconstant velocity. the distance traveled can help you measure your displacement if you take the same path home as you ran. your final velocity would be the velocity you are running as you finsh. if you have the time, distance and final or inital velocity of your run you can figure out your acceleration during your run as you picked up speed.
12. when sitting in a chair there is actually a lot of physics going on. the force of gravity is pushing you down towards the earth while the natural force of the chair is keeeping you from falling to the ground. the natural force and the force of gravity have to be exactly the same with a net force of 0 in order to keep you in place.
13. when throwing a ball there is a projectile and vertical and horizontal components. depending on the angle( 45 degree is max distance) the ball will travel a certain distance at a specific time. by figuring out the initial velocity and distance and time you can figure out the acceleration of the ball and the final velocity of the ball as it hit the ground. the vertical acceleration of an object is always 9.81 meters per second squared while the horizatal acceleration is 0. there are exact formulas in physics to figure out almost any calculation of the ball.
14. when driving there is a lot of physics involved. you have to accelerate your car to reach a certain speed limit. the velocity of your car is the speed you are going and the direction in which you are traveling. also if you are traveling to a location and than back home, displacement is happening. by going own the street to the store and than back up the street to your house your displacement would be zero because you end up where yyou atarted and went the same distance.
15. when i play fieldhockey there is a lot of pysics going on. when running down the feild my average velocity increases as i run faster. also as i go to hit the ball, the speed of my stick changes as i make contact with the ball becaue the force of the stick is slowed down due to hitting the ball. my displacement increseases and decreases depending on which way i am running on the field. when running up the field my displacement is increasing, if we loose possesion of the ball than i have to backpedel back down the field and my displacement decreases.
×
×
• Create New...