Answer:
The disintegrations is .
Explanation:
Given that,
Weight of sample = 200 g
Decay constant
We need to calculate the disintegrations
Using formula of disintegrations
Where, = decay constant
N = number of atoms present at time t
Put the value into the formula
Hence, The disintegrations is .
Answer:
80%
Explanation:
Efficiency = Power output / Power input × 100 %
To calculate efficiency we need to find power output of electric pump.
We can use,
Work done = Energy change
Work done per second = Energy change per second
Work done per second = Power
Therefore, Power = Energy change per second
= Change in potential energy of water per second
=mgh / t
= 200× 10×6 / 10
= 1200 W = 1.2 kW
Now use the first equation to find efficiency,
Efficiency = × 100%
= 80 %
It gets better
Yes it does
The answer is B
because if you compare a regular road and ice... ice is smoother and therefore has less friction
Answer:
Option D. ⁸⁵₃₆Kr
Explanation:
⁸⁵₃₅Br —> ⁰₋₁e + ?
Let ⁿₘZ represent the unknown.
Thus, the equation becomes:
⁸⁵₃₅Br —> ⁰₋₁e + ⁿₘZ
Next, we shall determine n, m and Z as follow:
85 = 0 + n
85 = n
Thus,
n = 85
35 = –1 + m
Collect like terms
35 + 1 = m
36 = m
Thus,
m = 36
ⁿₘZ => ⁸⁵₃₆Z = > ⁸⁵₃₆Kr
Thus, the equation:
⁸⁵₃₅Br —> ⁰₋₁e + ⁿₘZ
Becomes:
⁸⁵₃₅Br —> ⁰₋₁e + ⁸⁵₃₆Kr