Answer:
The half-life of the isotope is 2 hours
Explanation:
The Geiger counter is a device that is used for the detection and measurement of all types of radiation( that is alpha, beta and gamma radiation).
Initially, the Geiger counter also known as the Geiger Muller tube registers 160 counts per minutes when placed near a radioactive isotope. After eight hours, the counter registers 10 counts per minute, this reduced number of counts means that n half lives has elapsed.
10 counts per minute = 1/16 of 160 counts per minutes.
Therefore 1/16 = 1/2⁴, comparing 1/2⁴ with where n is the number of elapsed half lives, n = 4. This means that 4 half lives has elapsed after 8 hours.
Therefore one half life of the isotope = 8/4 = 2 hours.
Answer:
- Cool, dense air begins to sink downward.
- A high-pressure system forms.
- Pressure differences cause wind to blow outward.
- The skies clear, making way for pleasant weather.
Explanation:
The air near the land warms up and rises. Cool dense air sinks being heavier. This creates a pressure difference. A high pressure system forms. This difference leads to blowing of wind from High pressure to low pressure area. Eventually sky gets clear and we experience pleasant weather. Hence, the correct order to describe this is:
- Cool, dense air begins to sink downward.
- A high-pressure system forms.
- Pressure differences cause wind to blow outward.
- The skies clear, making way for pleasant weather.
DE = DC + CE
27 = 3v - 30 + 6v - 15
27 = 9v - 45
v = 8
Answer:
Explanation:
First, we have to calculate the maximum height reached by the object. We use the equations of uniformly accelerated motion:
In order to calculate this, we have to know the time taken by the object to reach the maximum height:
Now, we can calculate y:
Now, we calculate the time taken by the object in free fall:
Finally, adding and , we get the total time until the object impacts the ground:
Explanation:
Given data
The elevator mass=3.0×10³ kg
Time t=23 s
elevator lift d=210 m
The power is the average rate of work done:
So
P=F.V Cosα
Where F is force
V is velocity
α is angle between Force and velocity
Apply the Newton Law to find the force on elevator
The velocity of elevator is given as
Since the net force has same direction of motion so α=0°
So