posted by ice cream on .
Human skin (choose all that apply)
1. emits radiation well.
2. absorbs radiation well.
3. does not emit radiation well.
4. does not absorb radiation well.
5. has an emissivity of 0.
1 and 2 only :)
I agree. Human skin does most of its radiating in the 3 to 10 micrometer region of the infrared. Its average emissivity there is 0.97 of that of a black body, regardless of ethnicity. The average absorptivity for (visible) sunlight is lower, but still a rather high number.
a batter hits a baseball so that it leaves the bat with an initial velocity of 37.0 meter per seconds at an initial angle of 53.1 degrees, at a location where gravity is 9.8 meter per seconds squared. find the position of the ball and the magnitude and direction of its velocity, when time is equal to seconds. find the time when the ball reaches the highest point of its flight and find its height at this point. find the horizontal range r- that is the horizontal distance from the starting point, the point at which the ball hits the ground.for each treat the baseball as a projectile.