Answer:
3
Explanation:
The half-life is the time it takes for the amount of radioactive isotope to halve. Therefore, we have:
- After 1 half-life, only 1/2 of the element will be left
- After 2 half-lives, only 1/4 of the element will be left
- After 3 half-lives, only 1/8 of the element will be left
So, it will take 3 half-lives for the element to become 1/8 of its original amount.
Mathematically, this can be also verified by using the equation
where
N(t) is the amount of the element left at time t
N0 is the initial amount of the element
is the half-life
Substituting (3 half-lives), we find
Answer:
Explanation:
Given
Mass of first object
Mass of second object
Distance between them
object is placed between them
So force exerted by on
Force exerted by
So net force on is
i.e. net force is towards
(b)For net force to be zero on , suppose
So force exerted by and must be equal
Answer:
0.5 , 54.5
Explanation:
for acceleration we should derivate the equation 2 times
x=3t³+t²/4
v=9t²+t/2
a=18t+1/2
a(0)=0.5
a(3)=54.5
We know, speed = Distance / Time
d = 384,750 Km
t = 2 days, 19.5 hours = 48+19.5 = 67.5 hour
Substitute their values,
s = 384,750 / 67.5
s = 5700 Km/h
In short, Your Answer would be 5700 Km/h
Hope this helps!
Answer:
3000 J
Explanation:
Kinetic energy is:
KE = ½ mv²
If m = 15 kg and v = -20 m/s:
KE = ½ (15 kg) (-20 m/s)²
KE = 3000 J