Hi,

Can someone let me know if I'm correct please? Here I must use any of Nuton's law, so I use the second law. Thank you

A satellite will drop a small lander onto a planet moon's surface. At release, the vertical speed of the lander is zero. Neglecting all other forces except gravity, which you can assume to be constant, use your answer (4.4 m sZ) to calculate the vertical speed of the lander after 300 s. Answer: = 13 m s or 1.3 x 101 (both, in 2 sig-figs). Explanation: Using Newton's second law of motion I can use this formula: F=ma Where in this case: F: is the gravitational force. m: is the mass of the lander. a: is the acceleration. Since the only force on the lander is the force of gravity, and from my aquation above, the acceleration due to the gravity is 4.4 m s2. and I can write that F: =mx44ms2. The acceleration (a) of the lander is the force divided be the mass, so a: F m =44 ms+? Because the acceleration is constant, the velocity (v) of the lander after a certain time (t), can be found using this formula: v=u-+at Were (u) is the initial speed (or velocity) at: 0 m s as the lander is release from rest. Inserting the values, v: =0ms+44ms? =(4.4ms?2)x(300s) =1320 ms. Therefore, the vertical speed of the lander after 300 s is approximately 13 m s or 1.3 x 101 in scientific notation, both in two significant figures