You can use Newton's Second Law which states:

Plug in given information:

This is closest to option
b which is your answer.
Answer
given,
mass = 100 kg
acceleration = 10 m/s²
A mass 20 kg slides over 100 kg block
acceleration = 3 m/s²
horizontal friction exerted by the 100 kg block on 20 kg
using newton's second law
F - f = 0
F = f
f = ma
f = 20 × 3
f = 60 N
now net force acting on the 100 kg block
F_net = m a
F_net = 100 x 10
F_net = 1000 N
after 20 kg block falls the acceleration of the bock
F = 1000 +60
F = 1060 N
acceleartion on the block


a = 10.60 m/s²
Answer:
Mehar cant ride down the slope
Explanation:
She does not has a bicycle
Answer:
Resonance depends on objects, this may happen for example when you play guitar in a given room, you may find that for some notes the walls or some object vibrate more than for others. This is because those notes are near the frequency of resonance of the walls.
So waves involved are waves that can move or affect objects (in this case the pressure waves of the sound, and the waves that are moving the wall).
this means that the waves are mechanic waves.
Now, in electromagnetics, you also can find resonance frequencies for electromagnetic waves trapped in things called cavities, but this is a different topic.