(fast 20 points)

how do objects become electrically charged?

protons move from one object to another.

neutrons move from one object to another.

neutrons and electrons trade places.

electrons move from one object to another.

Ablock of mass m = 2.5 kg is attached to a spring with spring constant k = 740 n/m. it is initially at rest on an inclined plane that is at an angle of theta= 26 with respect to the horizontal, and the coefficient of kinetic friction between the block and the plane is uk = 0.17. 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. the block's initial mechanical energy is 9.472 j. 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.

Ascientist wants to test ways to reduce pollution in lake . what is the bestway of doing this

The first law of thermodynamics states that heat added to a system is neither created nor destroyed but is as it changes into other forms of energy.