Answer:
42.11 years old
Explanation:
Given that:
In 2000, a 20-year-old astronaut left Earth to explore the galaxy; her spaceship travels at 2.5 x 10^8 m/s. She returns in 2040
To find her age we use:
![\Delta t_m=\frac{\Delta t_s}{\sqrt{1-\frac{v^2}{c^2} } }\\](https://tex.z-dn.net/?f=%5CDelta%20t_m%3D%5Cfrac%7B%5CDelta%20t_s%7D%7B%5Csqrt%7B1-%5Cfrac%7Bv%5E2%7D%7Bc%5E2%7D%20%7D%20%7D%5C%5C)
Δtm is time interval for the observer stationary relative to the sequence of
events = 2040 - 2000 = 40 years
Δts is is the time interval for an observer moving with a speed v relative to the sequence of event
v = velocity = 2.5 x 10^8 m/s
c = speed of light = 3 x 10^8 m/s
![\Delta t_s=\Delta t_m}{\sqrt{1-\frac{v^2}{c^2} } }\\\Delta t_s=40\sqrt{1-\frac{(2.5*10^8)^2}{(3*10^8)^2}}\\\Delta t_s=22.11\ yr](https://tex.z-dn.net/?f=%5CDelta%20t_s%3D%5CDelta%20t_m%7D%7B%5Csqrt%7B1-%5Cfrac%7Bv%5E2%7D%7Bc%5E2%7D%20%7D%20%7D%5C%5C%5CDelta%20t_s%3D40%5Csqrt%7B1-%5Cfrac%7B%282.5%2A10%5E8%29%5E2%7D%7B%283%2A10%5E8%29%5E2%7D%7D%5C%5C%5CDelta%20t_s%3D22.11%5C%20yr)
Here age in 2000 is 20 year, therefore when she appear she would be 20 year + 22.11 year = 42.11 years old
1. calculate the value of acceleration that objects gains in that period of time
•calculating acceleration
5.50 = 1/2at^2
5.50*2/t^2 = a
11.00/0.657 = a
16.74=a
now you got the acceleration
2. you have laws of gravitation for that
g = Gm/r^2
where g is the acceleration value
16.74 = 6.754*10^-11 × m/ 6.28*10^4
105.14*10^4 /6.754*10-11 = m
15.567*10^15 = m
that would be the mass of the planet ...
Answer:
a) True
Explanation:
A program-specific message provided to an individual or group with the intention of raising awareness of a health condition, motivating behavior change, removing perceived barriers to participating in a health habit, or something else relating to the program's aims and objectives. The most effective intervention messages are usually theory-based and culturally adapted.
Answer:
connect two 9 ohms resistance in series now it becomes 18 ohm
... The top branch of the 3-branched parallel block ... the 9 and 6 in series ...
is equivalent to a single resistor of 15 ohms.
... The 3-branched parallel block boils down to (30, 10, and 15) in parallel.
That's (1/30 + 1/10 + 1/15)⁻¹ = 5 ohms.
... The 5-ohm-equivalent block and the 20-ohm resistor form a
voltage divider across the battery.
The voltage across the 5-ohm-equivalent block is (5/25 x 30v) = 6v .
... The top branch of the block is equivalent to a (9 + 6) = 15-ohmer.
With 6v across its ends, the current through that branch is (6/15) = 0.4A .
... With 0.4A flowing through it, the 9-ohm resistor is dissipating
I²R = (0.4A)² (9 ohms) = (0.16 A²) (9 ohms) = 1.44 W (choice-3)