The question is asking to calculate the object's speed v1, v2, v3 at the certain time is the given of the problem, in my calculation, I would say that the speed would be 2m/s, 1.5m/s, 0.22m/s. I hope you are satisfied with my answer and feel free to ask for more if you have question and further clarification
A pinhole camera<span> is a simple </span>camera<span> without a lens but with a tiny aperture, a</span>pinhole<span> – effectively a light-proof box with a small hole in one side. Light from a scene passes through the aperture and projects an inverted image on the opposite side of the box, which is known as the </span>camera<span> obscura effect.</span>
Answer:
The difference in the length of the bridge is 0.42 m.
Explanation:
Given that,
Length = 1000 m
Winter temperature = 0°C
Summer temperature = 40°C
Coefficient of thermal expansion 
We need to calculate the difference in the length of the bridge
Using formula of the difference in the length

Where,
= temperature difference
=Coefficient of thermal expansion
L= length
Put the value into the formula


Hence, The difference in the length of the bridge is 0.42 m.
Answer:
The iron atom has a positive charge, making it a cation.
Explanation:
The atom has a nucleus, where the protons and neutrons, which are the subatomic particles with the highest mass, are located. Practically all the mass of the atom is concentrated in the nucleus.Protons have a positive electrical charge, while neutrons have no charge.
Electrons move around the nucleus with other negatively charged particles.
An iron atom (Fe) has 26 protons and 20 electrons in it. That is, there are 6 more protons than electrons. As mentioned, protons are positively charged. So <u><em>the iron atom has a positive charge, making it a cation</em></u>.