Point charges q1=+2.00μC and q2=−2.00μC are placed at adjacent corners of a square for which the length of each side is 5.00 cm . Point a is at the center of the square, and point b is at the empty corner closest to q2 . Take the electric potential to be zero at a distance far from both charges.1. What is the electric potential at point a due to q1 and q2 ?2. What is the electric potential at point b ?A point charge q3 = -6.00 μC moves from point a to point b . How much work is done on q3 by the electric forces exerted by q1 and q2 ?

Density of salty water as compared to the density of pure water is(a) is less(b) is always equal(c) is always more(d) may be less or more

Ablock of mass m = 2.5 kg is attached to a spring with spring constant k = 710 n/m. it is initially at rest on an inclined plane that is at an angle of θ = 23° with respect to the horizontal, and the coefficient of kinetic friction between the block and the plane is μk = 0.19. in the initial position, where the spring is compressed by a distance of d = 0.16 m, the mass is at its lowest position and the spring is compressed the maximum amount. take the initial gravitational energy of the block as zero. a) what is the block's initial mechanical energy? b) if the spring pushes the block up the incline, what distance, l, in meters will the block travel before coming to rest? the spring remains attached to both the block and the fixed wall throughout its motion.

Ways that industry and agriculture use physical properties to separate substances