1. can a body have zero velocity and be acceleration?
2. can a body have constant speed and changing velocity?
3. can a body have constant velocity and changing speed?
4. if the speedometer of a car indicates a constant speed of 40 km/h, can you say that the car is not accelerating? why or why not?
5. if the instantaneous velocity doesn't change from instant to instant, will the average velocities for different intervals differ? why or why not?
2007-02-03 00:44:55 · 5 answers · asked by Anonymous in Science & Mathematics ➔ Physics
pls.prove your answer.
2007-02-03 00:47:10 · update #1
Speed and velocity are similar but not necessarily identical. Velocity (and acceleration) are vectors meaning that they represent travel in a fixed direction. If you drive in a circle you are traveling directly north only for and instant even though your speed is constant.
1. A body can have zero velocity and be accelerating, for example at the instant you release a rock and let it fall under the acceleration of gravity.
2. A body can have constant speed and changing velocity, for example a car driving in a circle.
3. A body can have constant velocity and changing speed, for example a car being driven at the same rate of change of distance in the north direction while going faster in the east direction (a curved path). There are separate instantaneous velocity vectors for north and east.
4. If the car indicates a constant speed of 40 km/h it may be accelerating every time it changes direction, for example a car driving in a circle is constantly changing direction.
5. If the instantaneous velocity doesn't change from instant to instant the average velocity may differ for different intervals if there is motion in two directions, for example velocity north is constant but velocity east is changing. The average of the two velocities (into a single vector) will change.
2007-02-03 01:49:36 · answer #1 · answered by Kes 7 · 0⤊ 0⤋
Speed is how far an object is travelling but Velocity is how fast and in which direction its travelling (Speed and Magnitude).......1:The body can be at 0 velocity and then start accelerating....2:A body can have constant speed and change direction only but not velocity..
2007-02-03 00:50:32 · answer #2 · answered by Anonymous · 0⤊ 0⤋
1. yes, because of gravity, a body is always accelerating.
2. no
3. no
4. no, because of gravity.
5. no, because if all instantaneous velocities are the same, they will average out to be the same.
It has been a couple of years since I took physics, but I got an A+ in the course. Double check my answeres, but I think they are right.
2007-02-03 00:49:43 · answer #3 · answered by theinfamous_eric 3 · 0⤊ 0⤋
Mechanics bargains with the Physics of action, velocity, acceleration and so on. Nuclear physics bargains with the reactions in the centre of atoms. Optics bargains with the behaviour of sunshine. there are various branches of physcis.
2016-10-01 08:49:17 · answer #4 · answered by mcfaul 4 · 0⤊ 0⤋
It would be best if you did your homework on your own instead of coming here and having others do it for you. If you don't learn the stuff know, you'll do horribly on the exam. How are we going to help you on your exam?
2007-02-03 01:01:12 · answer #5 · answered by Awesome Alisa 3 · 0⤊ 0⤋