All of them will have the same density
There's not enough information given to answer the question.
The speed depends on the kinetic energy of the bob at the bottom of
the first swing.
THAT depends on how high above its 'resting' position it was before
it was released, and THAT depends on how long the string is and
how far to the side you pulled it before you let it go.
<h2>
Answer:</h2>
3.0cm
<h2>
Explanation:</h2>
For lenses in an achromatic combination, the following condition holds, assuming the two lenses are of the same materials;
d = ---------(i)
Where;
d= distance between lenses
f₁ = focal length of the first lens
f₂ = focal length of the second lens
From the question;
f₁ = 4.5cm
f₂ = 1.5cm
Substitute these values into equation (i) as follows;
d =
d =
d = 3.0cm
Therefore, the distance between the two lenses is 3.0cm