The displacement is simply the difference in the position of the two marks and is independent of the path taken when traveling between the two marks. One way to think about this is to assume you marked the start of the motion and the end of the motion. Kinetic energy must always be either zero or a positive value. A car traveling at 60 mph has four times the kinetic energy of an identical car traveling at 30 mph, and hence the potential for four times more death and destruction in the event of a crash. In kinematics we nearly always deal with displacement and magnitude of displacement and almost never with distance traveled. This means that when the velocity of an object doubles, its kinetic energy quadruples. The equations shown here are actually vector equations and can be applied in each of the component directions. Scientists and mathematicians call this a vector quantity. In this case her displacement would be + 2 m +2 \text 1 5 0 m 150, start text, space, m, end text. The velocity, force, acceleration, and momentum have both a magnitude and a direction associated with them. For example, the professor could pace back and forth many times, perhaps walking a distance of 150 meters during a lecture, yet still end up only two meters to the right of her starting point. By magnitude, we mean the size of the displacement without regard to its direction (i.e., just a number with a unit). Also, speed is a scalar quantity but velocity and acceleration are vector quantities. People often forget that the distance traveled can be greater than the magnitude of the displacement.
0 kommentar(er)
