Similar elements with similar properties were in the same groups and periods for instance lithium(Li) and sodium(Na) are alkaline metals and so belong to the same group (that is group 1).Also Hydrogen(H) and Helium(He) both have only one shell or energy level and so belong to the same period.
I think the answer you’re looking for is
D)
-I hope this helps! Enjoy the rest of your day
Answer:
Solution given:
No of waves[N] =20crests & 20 troughs
=20waves
Time[T]=4seconds
distance[d]=3cm=0.03m
Now
<u>Wave</u><u> </u><u>length</u><u>=</u>3cm=3 × 
<u>Frequency</u>=
=
=5Hertz
and
Wave speed:wave length×frequency=3 × ×5=1.5 × 
.
Answer:
potential energy PE = M g h
KE at bottom = 1/2 M V^2
Regardless of the slope of the slide the change in energy is the same
1/2 V^2 = g h
V = (2 g h)^1/2 = (2 * 9.8 m/s^2 * 10 m)^1/2 = 14 m / s
Perhaps the question says that h = 55 * .1 = 5.5 m
Then V = (2 * 9.8 * 5.5) = 10.4 m/s
