A spike is hammered into a train rail. You are standing at the other end of the rail. You hear the sound of the hammer strike both through
the air and through the rail itself. These sounds arrive at your point
six seconds apart. You know that sound travels through air at 1100
feet per second and through steel at 16,500 feet per second. How far
away is that spike? (Round to one decimal place.)

If square root x = -7, then x= -49 true or false

Given right triangle a w/a hypotenuse length of x+4 and a leg of x, and right triangle b, w/ a hypotense length of 3y and a leg length of y+4 for what values of x and y are the triangles congruent by hl?

Stu and ambrose are working together on a study of whether diet is related to students' mental health. first, they randomly select 10 students from the student center and 10 students from the office of counseling and psychological services. then, they ask students to rate their diet in terms of healthiness on a scale of 1-100 before completing a 20-item mental health survey. a) name one of the constructs being studied b) how was the construct you named above operationally defined in this experiment? e) was the variable you described above their independent variable, their dependent variable, or a controlled variable? d) what is a confounding variable? what is a potential confound in this study?