The elements which have similar behavior are Barium, strontium and beryllium.
Answer
given,
mass of block (m)= 6.4 Kg
spring is stretched to distance, x = 0.28 m
initial velocity = 5.1 m/s
a) computing weight of spring
k x = m g


k = 224 N/m
b) 




c) 


d) 


e)


A = 0.682 m
Force =
=
F = 94.20 N
Answer:
3.0 cm
Explanation:
We can solve this problem by using the mirror equation:

where
f is the focal length of the mirror
p is the distance of the object from the mirror
q is the distance of the image from the mirror
In this problem we have:
f = 1.5 cm is the focal length of the mirror (positive for a concave mirror)
p = 3.0 cm is the distance of the object from the mirror
Therefore, the distance of the image is:

And the positive sign means that the image is real.
(The second part of the exercise is just the description of the image of the first exercise).
I agree with the other comment
Answer:
longitudinal waves have those properties