Astudent tries to raise a chain consisting of three identical links. each link has a mass of 300 g . the three-piece chain is connected to a string and then suspended vertically, with the student holding the upper end of the string and pulling upward. because of the student's pull, an upward force of 15.0 n is applied to the chain by the string. use newton's laws to answer the following questions.
find the acceleration of the chain. take the free fall acceleration to be g. find the force exerted by the top link on the middle link.

You can watch static electricity in action by rubbing an inflated balloon against your hair. your hair will actually stand on its end! it does this because each hair becomes charged, and they all repel one another.

The base of a 50-meter tower is at the origin; the base of a 50-meter tree is at (0, 50, 0). the ground is flat and the z-axis points upward. the following parametric equations describe the motion of six projectiles each launched at time t = 0 in seconds. (i) r (t) = (50 + t2)k (ii) r (t) = 2t2 j + 2t2k (iii) r (t) = 50 i + 50 j + (50 − t2)k (iv) r (t) = 2t j + (50 − t2)k (v) r (t) = (50 − 2t) i + 2t j + (50 − t)k (vi) r (t) = t i + t j + tk (a) which projectile is launched from the top of the tower and goes downward? at time t = , the projectile hits the ground at point (x, y, z) = . (b) which projectile hits the top of the tree?

Is a volume of space that is empty of matter.