tamara wants to investigate the effect of mass on a toy truck rolling down a ramp. she uses a motion sensor to measure the final speed of the toy truck at the bottom of the ramp. tamara begins with an empty toy truck, releases it down the ramp and records its speed. she then adds 50 grams (g) of mass to the toy truck and measures the truck's speed. what is the outcome variable (dependent variable) in this experiment?

The smokey mountains have over 2,100 miles of rushing mountain streams and rivers that flow through the park. in each mile lives a diverse community of native fish, amphibians, insects, and larvae, some of which are found only in the southern appalachians. park managers and scientific researchers test many factors such as fish populations, the watersheds and water tests to determine a) too many lizards are present b) the water quality of the stream c) rainwater is running into local streams d) if visitors to the park are overstaying their welcome