Extra Credit  An astronaut on a certain planet releases a 15 kg object from a height of 25 m above the surface and measures the time it takes for the object to hit the ground to be 1.97s. (i).  Calculate the acceleration due to gravity on this unknown planet.             (1.5 points)                                                                                                                                                                                                                                                                     (ii). At what speed does the object hit the surface of the planet?                                                                          (1.5 points)   (iii). What is the mass of the object just before it hits the floor of the planet?                                                        (1.0 point)  

    In the absence of air resistance, a projectile launched at an angle of 15 o above the horizontal will have the same       range as a projectile launched at which of the following angles?                                                                             

2.5 kg and 3.0 kg mass are released 25 m above ground (neglect air resistance)  

What will happen if switch 3 is closed and the other switches are left open?

Resistance is a measure of how difficult it is for electrons to flow through a substance. What is the unit used for measuring resistance?

What happens when silk is rubbed on a glass rod?  

What is the equation that represents Ohm’s law?

In the circuit shown, if the resistor at X is 20Ω the resistor at Y is 10 Ω, and the resistor at Z is 25 Ω, where would the current be greatest?  

Which of the following is an unsafe location to be during a lightning storm?

The strength of a battery is determined by the potential difference between two points on the circuit contained within the battery. What is the common term used to describe this strength, or potential difference?