Answer: d) 312.5 mg
Explanation:
This problem can be solved using the Radioactive Half Life Formula:
Where:
is the remaining amount of Actinium-226
is the initial amount of Actinium-226
is the time elapsed
is the half life of Actinium-226
Knowing this, let's find :
The phenomenon which is responsible for this effect is called diffraction.
Diffraction is the ability of a wave to propagate when it meets an obstacle or a slit. When the wave encounters the obstacle or the slit, it 'bends' around it and it continues propagate beyond it. A classical example of this phenomenon is when a sound wave propagates through a wall where there is a small aperture (as in the example of this problem)
Answer:
Explanation:
A ) The surface is frictionless . If the box is at rest , there will be no tension in the rope.
B ) In this case , the box is moving with steady rate of 4.20 m /s . In this case also no force is acting on the box so tension in the rope will be nil.
C ) In this case the box is moving with acceleration of 5.8 m /s² so force on the box = mass x acceleration
= 57 x 5.8
= 330.6 N .
So tension in the rope will be equal to force acting on the rope . Hence tension = 330.6 N .
A. a steel beam. All of the rest of them change shape or volume whereas a steel beam with never change in volume or shape.
