Some people wish that we lived in a recollapsing universe that would eventually stop expanding and start contracting. for this to be the case, which of the following would have to be true (based on current (a) dark energy is the dominant form of energy in the cosmos. (b) dark energy does not exist and there is much more dark matter than we are aware of to date. (c) neither dark energy nor dark matter really exist. (d) dark energy exists but dark matter does not.

We all use gps today, even if we don't drive yet. i bet you have been in the car with a parent and they have asked you to get out your phone to find a specific location. in your car, on the phone, you are using a very sophisticated technology. gps satellites circle the earth twice a day in a very precise orbit and transmit signal information to earth. gps receivers take this information and use trilateration to calculate the user's exact location. essentially, the gps receiver compares the time a signal was transmitted by a satellite with the time it was received. the time difference tells the gps receiver how far away the satellite is. now, with distance measurements from a few more satellites, the receiver can determine the user's position and display it on the unit's electronic map. what type of signal is utilized by the gps satellite?

(2) (a) you have a simple circuit that consists of only a battery (δvbat=1.5v) and two resistors with resistance r1=10ω and r2=5ω, connected in series with each other. what is the current running through the battery? (b) you re-arrange your circuit so now r2 is attached in parallel to r1 rather than in series. what is the current running through the battery? (c) you add an additional resistor r3=7ω on the same branch as r2. what is the current running through the battery? (d) what is the power dissipated in r3?

A10 kg box initially at rest is pulled 18 meters across a horizontal, frictionless surface by a 40 n force. what is the block’s final velocity over the 18 meters?