Time period of any moon of Jupiter is given by

from above formula we can say that mass of Jupiter is given by

now for part a)

T = 1.77 day = 152928 seconds
now by above formula



Part B)

T = 3.55 day = 306720 seconds
now by above formula



Part c)

T = 7.16 day = 618624 seconds
now by above formula



PART D)

T = 16.7 day = 1442880 seconds
now by above formula



D. 980, this is the best answer because 35 x 7 is 980 :)
Question 18: a
question 19: b
question 20: c
Answer:
the object's mass is 50 kg
Explanation:
We use Newton's second law to solve for the mass:
F = m * a , then m = F / a
In our case, the acceleration is the gravitational acceleration on the planet, and the force is the weight of the object on the planet. So we get:
m = w / a = 650 N / 13 m/s^2 = 50 kg
Then, the object's mass is 50 kg.