ACTIVITY 4: push with your fingers on something that moves (binder, empty chair, etc.) when you push it like a chair. Notice what’s happening to your fingers. Is anything pushing on them while they are pushing and moving the chair? Explain. ACTIVITY 5: grab two of the same coins. Placed one coin on a smooth surface. Slide the second coin toward the first coin and keep trying until you hit the first coin with the second coin. What happens to the coin that was at rest (1st)? What happened to the coin that was moving(2nd)?

ACTIVITY 6: stand up. Begin to walk forward. When you stand at rest and then move forward, you have changed your velocity. That requires a force. Would extended the force on you to change your velocity? (Hint- you can’t push yourself- some thing else has to push you forward). Justify your answer.

Consider a system with two masses that are moving away from each other. why will the kinetic energy differ if the frame of reference is a stationary observer or one of the masses?

To understand the behavior of the electric field at the surface of a conductor, and its relationship to surface charge on the conductor. a conductor is placed in an external electrostatic field. the external field is uniform before the conductor is placed within it. the conductor is completely isolated from any source of current or charge. part a: which of the following describes the electric field inside this conductor? it is in the same direction as the original external field.it is in the opposite direction from that of the original external field.it has a direction determined entirely by the charge on its surface.it is always zero. part b: the charge density inside the conductor is: 0non-zero; but uniformnon-zero; non-uniforminfinite part c: assume that at some point just outside the surface of the conductor, the electric field has magnitude e and is directed toward the surface of the conductor. what is the charge density η on the surface of the conductor at that point? express your answer in terms of e and ϵ0

The friction of the water on a boat produces an acceleration of -10. m/s2. if the boat is traveling at 30. m/s and the motor is shut off, how long it take the boat to slow down to 5.0 m/s?