Why do elements need to be heated to emit color?

What is the difference between: first moment of area and second moment of area?

While hovering motionless 3.0 meters an asteroid, a small

Gold has a specific heat of 129 J/kg°C. How many joules of heat energy are required to raise the temperature of 0.015 kilograms of gold from 22°C to 85°C? 144

Which statements describe the applications of nuclear medicine scans? Check all that apply. O assess disease progression and tissue function utilize ultrasound utilize a biologically active molecule require a CT scan utilize a radionuclide tracer

Alex collides with a desk as he runs through his office. If the combined momentum of Alex and the desk was 400 kg•m/s to the north before the collision, what is their combined momentum after the collision?

What is the purpose of using a wedge? A. separates objects B. keeps objects together C. allows you to exert force over a distance

Echolocation is an acoustic principle in which some wildlife use resonance to find food at night. Question 25 options: True False

Use the drop-down menus to identify the variables for the second hypothesis. Hypothesis #2: As you build circuits, you will alter resistance, which is the y variable.

A tortoise travel 15 meters west, then another 13 centimeters west. How many total has the tortoise walked?

How does genetic drift affect small populations differently than large populations?