# A+ Work - If a certain force accelerates

1. If a certain force accelerates an object of mass 27 Kg at 50 m/s/s, what acceleration in m/s/s would the same force produce on another object of mass 27? Enter answer to at least one decimal place to the right of the decimal point.
2. Given that the acceleration of gravity at the Earth's surface is about 980 cm per sec per sec, the centripetal acceleration [v squared over r] of an artificial satellite in a circular orbit with a radius 3.9 times that of the Earth's radius would be about _____ cm per sec per sec. (Hint: F = m a, and the force of gravity gets weaker as the square of the distance, so how much weaker is gravity at 3.9 times the Earth's Radius than it is at the surface of the Earth?)

3. If a hypothetical planet in our Solar System had a sidereal period of 11.1 Earth years and a circular orbit, how far from the Sun in Astronomical Units would it be? Enter your answer to the nearest 0.01 AU.

4. If a particular galaxy has a total mass of 10 to the 56 grams and the average star in that galaxy has a mass of 10 to the 35 grams, approximately how many stars are there in that galaxy? Give your answer to the nearest whole power of 10 by entering the exponent only.