Một dây chì có đường kính tiết diện ngang 1,2 mm. Nếu mật độ dòng điện giới hạn của chì là 450 A/cm2 sẽ thì cường độ dòng điện giới hạn chạy qua dây chì này là bao nhiêu?

Answertraveling around a circular trackexplanation"traveling around a circular track" is the best answer as you could be traveling around a circular track at a constant speed. your velocity would therefore have the same magnitude but will always be constantly direction. since acceleration is the rate of change of velocity, the rate of change will only involve the direction of velocity and not the magnitude.wrong choices: "an object at rest" does not accelerate at all"increasing speed while traveling around a curve" means that the acceleration will not be constant due to only change in direction; it will be constant due to both magnitude and direction"an object in free fall" does not necessarily change direction 

You need to be more specific.  i really don't know what a "motion map" is.you can draw a graph of an object's position, distance, displacement, speed,velocity, or acceleration versus time, or you can draw a graph of the object's x-position versus its y-position and not give any information about time at all.if the graph presents position or displacement against time,  then constant velocity is a straight line . . i.e. a line that has  constant slope.if the graph shows speed against time, then constant velocityis a horizontal piece of line.if the graph shows acceleration against time, then constant  velocity is a piece of line that lies on the x-axis . . it's value is zero. 

Ithink the answer is d

In psychology, a person who thinks that upbringing and environment are much more important than genes is more on the side of in the nature versus nurture debate.the answer in the blank is letter b which is nature. they are more on the nature and environmental side than the genetic side of species.