Answer:
-ripples on the surface of water.
-vibrations in a guitar string.
-a Mexican wave in a sports stadium.
-electromagnetic waves – eg light waves, microwaves, radio waves.
-seismic S-waves.
Explanation:
I've done this question before
In order to calculate the weight, we may simply use:
W = mg
W = 30 * 9.81
W = 294.3 N
The sum of the reaction force and the upward component of child pulling will be equal to total downward force. The force acting downwards is the weight. Therefore:
R + 12sin(45) = 294.3
R = 285.82 N
The acceleration can be found using the resultant force and the mass of the sled. The resultant force is:
F(r) = pulling force + pushing force - friction
F(r) = 12cos(45) + 8 - 5
F(r) = 11.48 N
a = F/m
a = 11.48 / 30
a = 0.38 m/s²
Answer:
The answer to this problem is 290.16m/s
