The crab pulsar winds down. theoretical models indicate that the age of a pulsar is about p/(2r), where p is the pulsar’s period, and r is the rate that the pulsar slows with time. the pulsar in the crab nebula is pulsing 30 times a second (so p = 0.0333 seconds). but the time interval between pulses is actually growing longer by 4.2x10-13seconds with each passing second (so r = 4.2x10-13 seconds per second). knowing this, how old is the crab pulsar? how does your age compare to the true age of the pulsar, which was born in the supernova observed in a. d. 1054?

What is the approximate circumference of the circle shown below? 12.2 cm

On nights when we see the new moon phase, what side of the moon are we seeing?

Imagine you work as a consultant, and your daily job involves listening to the constructive criticism of others. as part of your job, you must listen to opposing viewpoints to make important decisions. in this activity, you are a consulting dam engineer. you must make a decision about four different dams; should they be repaired, taken down, or left alone? you will listen to contrasting opinions about what should be done with the dams before you make the final decision. as the consulting dam engineer, what do you decide to do with this dam? explain your reasoning. by making your decision, did you support the opinions of the mayor and/or the dam safety official? why or why not? (site 1)