Answer:
It would take two half-lives which would be 130days
The substance has a half-life of 30 minutes. There has been two cycles that have occurred.
idk the last one
Explanation:
The mass of fuel the engine burn each second to produce a thrust of 7.66×10⁵ N is 2.5×10² kg/s.
<h3 /><h3>What is mass?</h3>
Mass can be defined as the quantity of matter contained in a body. The S.I unit of mass is kilogram(kg)
To calculate the mass the engine burns each seconds, we use the formula below.
Formual:
- M = T/v............. Equation
Where:
- M = Mass per seconds of the rocket
- T = Thrust
- v = Velocity
From the question,
Given:
- T = 7.66×10⁵ N
- v = 3.05×10³ m/s
Substitute these values into equation 1
- M = (7.66×10⁵)/(3.05×10³)
- M = 2.5×10² kg/s
Hence, the mass of fuel burned in each second is 2.5×10² kg/s.
Learn more about mass here: brainly.com/question/25121535
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Answer:
750 people
Explanation:
From the question,
Number of people in the city = population density×Area of the city
N = D×A.......................... Equagtion 1
Where N = Number of people in the city, D = population density, A = Area of the city.
Given: D = 50 people per square kilometer, A = 1.5×10 square kilometer.
Substitute into equation 1
N = 50(1.5×10)
N = 750 people.
Hence the total number of people in the city is 750 people.
Answer:
The equivalent stiffness of the string is 8.93 N/m.
Explanation:
Given that,
Spring stiffness is





According to figure,
and
is in series
We need to calculate the equivalent
Using formula for series


Put the value into the formula


k and
is in parallel
We need to calculate the k'
Using formula for parallel

Put the value into the formula


,k' and
is in series
We need to calculate the equivalent stiffness of the spring
Using formula for series

Put the value into the formula


Hence, The equivalent stiffness of the string is 8.93 N/m.