Answer:
Explanation:
The relation between activity and number of radioactive atom in the sample is as follows
dN / dt = λ N where λ is disintegration constant and N is number of radioactive atoms
For the beginning period
dN₀ / dt = λ N₀
58.2 = λ N₀
similarly
41 = λ N
dividing
58.2 / 41 = N₀ / N
N = N₀ x .70446
formula of radioactive decay
- λ t = ln .70446 = - .35
t = .35 / λ
λ = .693 / half life
= .693 / 5715
= .00012126
t = .35 / .00012126
= 2886.36
= 2900 years ( rounding it in two significant figures )
Answer:
831.4 J
Explanation:
Info given:
mass adult: 82.5kg
mass child: 14.7kg
height of wall: 1.25m
g = 9.81m/s^2
PE = mgh
For adult:
mgh = (82.5kg)(9.81m/s^2)(1.25m) = 1011.65 J
For child:
mgh = (14.7kg)(9.81m/s^2)(1.25m) = 180.25 J
Difference in PE: 1011.65 J - 180.25 J = 831.4 J
Answer:
92 elemns in mendeleef oisv
bitly coin download
Explanation:
Answer:
9.495 m/s
Explanation:
initial horizontal speed, ux = 2.60 m/s
initial vertical speed, uy = 0
height, h = 4.60 m
acceleration due to gravity, g = 9.8 m/s^2
Let the speed of fish is v as it hits the water level.
Use third equation of motion in vertical direction
v = 9.495 m/s
Thus, the fish hits the water level with the speed of 9.495 m/s.
The larger the mass the mass and the speed, the larger the force it would produce if it crashes something. Some car crashes produce minor injuries because maybe this car is small and runs at very slow speed which would mean less force when in impact with another. However, if a big truck crashes, it is expected to produce a larger force causing catastrophic injuries.
