3. an astronaut lands on an alien planet. he places a pendulum (l = 0.200 m) on the surface and sets it in simple harmonic motion, as shown in this graph.

answer the following questions:
a. what is the period and frequency of the pendulum’s motion?
b. how many seconds out of phase with the displacements shown would graphs of the velocity and acceleration be?
c. what is the acceleration due to gravity on the surface of the planet in m/s2? determine the number of g-forces.

a).  We could read off the period if we had the graph.
      The frequency is 1/period.

b).  The velocity is the first derivative of the displacement,
       so it should lag the displacement by 90° .
 
       The acceleration is the derivative of the velocity,
        so that puts it 180° behind the displacement.

c).  If we could see the graph, then, knowing the pendulum's
      length and the period of its swing, we could calculate the
      acceleration of gravity on the planet at which he is at.

      The number of 'G-forces' is

                   9.8 m/s² / (acceleration of gravity where he is at) .

       The number is a ratio ... without units.     

Ithink the answer would be 1,350!

Answer: it will take   4.36 seconds to reach her average velocity 10.69 miles/hour.explanation:   we have equation of motion ,where s is the displacement, a is the acceleration, u is the initial velocity and t is the time taken.average velocity = displacement/ time taken.average velocity = 10.69 miles/hr = 10.69*1.6*1000/(60*60) = 4.75 m/s4.75 = s/ts = 4. 1we also have acceleration = 2.18 m/s², initial velocity = 0 m/sso it will take   4.36 seconds to reach her average velocity 10.69 miles/hour.