Hydrogen is in group 1 with lithium, sodium, potassium, rubidium, cesium, and francium because it
(2 points)
Is a metal
Is a gas
Has 1 valence electron
Has 1 energy level

A200-n force is applied to the foot-operated air pump. the return spring s exerts a 2.6-n·m moment on member oba for this position. determine the corresponding compression force c in the cylinder bd. if the diameter of the piston in the cylinder is 40 mm, estimate the air pressure generated for these conditions. state any assumptions. enter a positive number for the compression force c.

The particle p starts from rest at point a at time t = 0 and changes its speed thereafter at a constant rate of 2.8g as it follows the horizontal path shown. determine the magnitude and direction of its total acceleration (a) just before point b, (b) just after point b, and (c) as it passes point c. state your directions relative to the x-axis shown (ccw positive) and choose the angle with the smallest magnitude.

Achild has maximum walking speed of 1.6 m/s. what is the length of the child's legs? 0.26 m