This question is on space and projectiles. It is about comet 67P/ Churyumov-Gerasimenko and the Rosetta/ Philae lander. Question: 67P has a gravitational field strength of 5.2x10^5 N/Kg. After Philae bounced it took 1 hour 50 minutes to reland. Calculate the initial velocity of Philae. Does this seem to be a realistic value? You are allowed to get other information that you need off the internet to answer the question however, I do not know how the gravitational field strength comes into play. I'm preety sure you use u = Initial velocity, v = Final Velocity, t = time taken, s = distance traveled or displacement, a = acceleration. The time taken is 6600 secs. But i still need to find the acceleration, distance traveled and final velocity. I'm sure we cannot just use the distance traveled off the internet because the next question asks us to find it. I guess i can find the force applied to Philae using F=mg but i'm not sure how that would help me but it uses the gravitational field strength which is given?