Answer:
V1 =8.1 m/s
Explanation:
height at highest point (h2) = 4.1 m
height at lowest point (h1) = 0.8 m
acceleration due to gravity (g) = 9.8 m/s^{2}
from conservation of energy, the total energy at the lowest point will be the same as the total energy at the highest point. therefore
mgh1 + 
= mgh2 + 
where
- speed at highest point = V2
- speed at lowest point = V1
- mass of the girl and swing = m
- at the highest point, the speed is minimum (V1 = 0)
- at the lowest point the speed is maximum (V2 is the maximum speed)
- therefore the equation becomes mgh1 + = mgh2
m(gh1 + 
) = m(gh2)
gh1 + = gh2
V1 = 
now we can substitute all required values into the equation above.
V1 = 
V1 = 
V1 =8.1 m/s
Answer:
Amount of radioactive particles left after 60 years = 100 particles.
Explanation:
Amount of radioactive particles before 60 years = 400
Amount of radioactive particles present today = 200
That is radio active particles reduced to half. That is 60 years is half life of this radio active material.
After 60 years this 200 radio active particles will reduce to half.
Amount of radioactive particles left after 60 years = 0.5 x 200 = 100 particles.
I'm pretty sure they expand
If it runs 6 miles in half an hour multiply 6 by two then there is your answer
here's the solution,
The <em>radius</em> of the circle =<u> 3 km</u>
distance covered = <em>circumference</em> of the circle,
So, Circumference :
=》
=》
=》
(a). Distance covered by moving object is 18.84 km
(b). 0 km
now, Displacement of the object is 0 km, because displacement is the shortest distance from stating point to the destination, but the object returns back to the starting point, hence magnitude of displacement is 0.
