(263.1 years) x (half-life / 87.7 years) = 3 half-lifes
In 3 half-lifes, (1/2 x 1/2 x 1/2) = 1/8 of the atoms in a sample remain unchanged.
That's 12.5% that remain unchanged.
The other 87.5% of the atoms in the sample have decayed, and changed to either other isotopes of plutonium or into atoms of other elements.
Answer:
a. The station is rotating at
b. the rotation needed is
Explanation:
We know that the centripetal acceleration is
where is the rotational speed and r is the radius. As the centripetal acceleration is feel like an centrifugal acceleration in the rotating frame of reference (be careful, as the rotating frame of reference is <u>NOT INERTIAL,</u> the centrifugal force is a fictitious force, the real force is the centripetal).
<h3>a. </h3>
The rotational speed is :
Knowing that there are in a revolution and 60 seconds in a minute.
<h3>b. </h3>
The rotational speed needed is :
Knowing that there are in a revolution and 60 seconds in a minute.
Answer:
45 N
Explanation:
From the question given above, the following data were obtained:
Force applied by Brett = 25 N
Force applied by Chris = 20 N
Net force =?
From the question given above, Brett and Chris applied force to the piano in the same direction. Thus the net force acting on the piano will be the sum of the forces applied by Brett and Chris. This can be obtained as follow:
Force applied by Brett = 25 N
Force applied by Chris = 20 N
Net force =?
Net force = 25 + 20
Net force = 45 N
This is true.
Hope this helps
consider the motion along the X-direction
X = horizontal displacement = 80 m
= initial velocity along the x-direction = v Cos60
t = time of travel
using the equation
X = t
80 = (v Cos60) (t)
t = 160/v eq-1
consider the motion in vertical direction :
Y = vertical displacement = 20 m
= initial velocity in Y-direction = v Sin60
a = acceleration = - 9.8 m/s²
t = time of travel = 160/v
using the equation
Y = t + (0.5) a t²
20 = (v Sin60) (160/v) + (0.5) (- 9.8) (160/v)²
v = 32.5 m/s