Answer:
t ’=
, v_r = 1 m/s t ’= 547.19 s
Explanation:
This is a relative velocity exercise in a dimesion, since the river and the boat are going in the same direction.
By the time the boat goes up the river
v_b - v_r = d / t
By the time the boat goes down the river
v_b + v_r = d '/ t'
let's subtract the equations
2 v_r = d ’/ t’ - d / t
d ’/ t’ = 2v_r + d / t
In the exercise they tell us
d = 1.22 +1.45 = 2.67 km= 2.67 10³ m
d ’= 1.45 km= 1.45 1.³ m
at time t = 69.1 min (60 s / 1min) = 4146 s
the speed of river is v_r
t ’=
t ’=
In order to complete the calculation, we must assume a river speed
v_r = 1 m / s
let's calculate
t ’=
t ’= 547.19 s
Answer:
The mass of Neptunium is 237.054 u.
Explanation:
Given that,
Mass of Americium = 241.05682 u
Mass of alpha particle = 4.00260 u
The equation is,

Let the mass of Neptunium is m.
Since the mass remain same.
We need to calculate the mass of Neptunium
Using formula of mass
Mass of Neptunium = Mass of Americium -Mass of alpha particle
Put the value into the formula


Hence, The mass of Neptunium is 237.054 u.
I would say unlimited polarity because the compass’s needle is always attracted to Earth’s north pole.
Good luck to you!
Answer:
The speed at the aphelion is 10.75 km/s.
Explanation:
The angular momentum is defined as:
(1)
Since there is no torque acting on the system, it can be expressed in the following way:




(2)
Replacing equation 1 in equation 2 it is gotten:
(3)
Where m is the mass of the comet,
is the orbital radius at the aphelion,
is the speed at the aphelion,
is the orbital radius at the perihelion and
is the speed at the perihelion.
From equation 3 v_{a} will be isolated:
(4)
Before replacing all the values in equation 4 it is necessary to express the orbital radius for the perihelion and the aphelion from AU (astronomical units) to meters, and then from meters to kilometers:
⇒ 
⇒ 
⇒
⇒
Then, finally equation 4 can be used:


Hence, the speed at the aphelion is 10.75 km/s.