Two spheres (one with a 12 cm radius, the other with a 18 cm radius) are separated by a distance of 50 cm from surface to surface. each sphere has a charge density of 1.2 nc/m3. what is the force on the 12 cm sphere? 2. from problem 1, what is the electric field at the midpoint between the center of the spheres

Apulley with a mechanical advantage of 5 will require you to pull times the amount of rope. a. 1/5 b. 5 c. 10 d. 15

•• al and bert are jogging side-by-side on a trail in the woods at a speed of 0.75 m/s. suddenly al sees the end of the trail 35 m ahead and decides to speed up to reach it. he accelerates at a constant rate of 0.50 m/s2, while bert continues on at a constant speed. (a) how long does it take al to reach the end of the trail? (b) once he reaches the end of the trail, he immediately turns around and heads back along the trail with a constant speed of 0.85 m/s. how long does it take him to meet up with bert? (c) how far are they from the end of the trail when they meet?

Select the word from the list that best fits the definition classification of most stars on the h-r diagram