Space rover weighs 100 n on earth while a different space rover weighs 100 n on the moon
when you compare the masses of the two space rovers, which rover has the greater mass?

The second rover has a greater mass.

Explanation:

Given data,

The weight of the space rover on earth, W = 100 N

                                       W = mg

                                        m = W /g

                                            = 100 / 9.8

                                            = 10.2 kg

Hence, the mass of the space rover on earth is, m = 10.2 kg

The weight of the different space rover on moon W' = 100 N

                                        W' = mg'

                                         m = W'/g'

                                             = 100 / 1.6   (acceleration due to gravity on moon g' = 1.6 ,m/s²)

                                          m = 62.5 kg

Hence, the second rover has a greater mass.

B. that particle will remain stationary due to interference. 
as both waves are equal in amplitude and wavelength and are moving in opposite directions, then destructive interference will occur, the two waves will cancel each other's effects. this destructive interference will cause the particle to remain stationary