Answer:
A 1.0 min
Explanation:
The half-life of a radioisotope is defined as the time it takes for the mass of the isotope to halve compared to the initial value.
From the graph in the problem, we see that the initial mass of the isotope at time t=0 is

The half-life of the isotope is the time it takes for half the mass of the sample to decay, so it is the time t at which the mass will be halved:

We see that this occurs at t = 1.0 min, so the half-life of the isotope is exactly 1.0 min.
A) leaving a copper penny in vinegar until it turns green
Answer:
velocity = distance / time taken
= 200/4
= 50 m/s
is the correct answer
Answer:

Explanation:
From the question we are told that:
Mass 
Speed 
Mass 
Speed 
Generally the equation for Magnitude of the Third piece is mathematically given by


Where



And


Therefore


Answer:
A - They are both electromagnetic waves.
Explanation:
Electromagnetic waves are waves consisting of periodic oscillations of electric and magnetic fields, that vibrate in a plane perpendicular to the direction of propagation of the wave (for this reason, they are said to be "transverse waves").
Electromagnetic waves, unlike mechanical waves, can travel through a vacuum, and do not need a medium to propagate. Their speed in a vacuum is a constant and it is called speed of light (
).
Electromagnetic waves are classified, depending on their wavelength and frequency, into 7 different types - together they form the electromagnetic spectrum. The 7 types, listed from shortest to longest wavelength, are:
gamma rays
X-rays
ultraviolet radiation
visible light
infrared radiation
microwaves
radio waves
All these waves, despite having different properties, are all electromagnetic waves -so we see that both radio waves and gamma rays belong to this type of waves.