Missing part of the text:
"Two masses, m1 = 2.12 kg and m2 = 9.01 kg are on a horizontal frictionless surface and they are connected together with a rope as shown in the figure."
and missing figure (see attachment)
Solution:
We can write Newton's second law for the whole system m1-m2 and for m2 only (2 equations). Only one force (F) acts on the m1-m2 system, while if we consider m2 only we have two forces acting on it: F and T (tension), in the opposite direction. So, the two equations are
where a is the acceleration of the system.
From the first equation we get
and substituting it inside the second equation, we get
re-arranging, we get
Using
,
, and using the maximum value of T that is allowed not to break the rope (T=55 N), we can find the maximum allowed value for F:
Answer:
<em>she'll be 42.3 years old</em>
<em></em>
Explanation:
The year she left is 2020
she returns in 2040
the time observed to have passed by on earth is 40 years
she traveled at a speed of 2.5 x 10^8 m/s
From relativity, the astronaut will experience a time dilation and will age more slowly.
the time that is observed to pass on her ship will be gotten from
t' =
where t is the time that is observed to pass by an earthly observer
v is the speed of her ship
c is the speed of light = 3 x 10^8 m/s
v/c = 2.5/3 = 0.83
t' = = 40 x 0.5578 = <em>22.3 years</em> would have passed for her
This means that she'll be 20 + 22.3 = <em>42.3 years old</em>
Answer:
14.3 km
Explanation:
We motion of the car consists is split in two parts:
- A first motion 12 km north
- A second motion 7.8 km west
The two motions are in directions perpendicular to each other: this means that we can find the magnitude of the net displacement by using Pythagorean's theorem, therefore:
where
Substituting, we find