Answer:
The crops will have the ability to be resistant to certain diseases
The presence of helium gas indicates the radioactive sample is most likely decaying by α-decay, or alpha decay. α-decay is the type of radioactive decay in which an atomic nucleus emits α particles. α particles are Helium nuclei. So the correct answer would be α-decay.
Answer:
a)-1.014x 
J
b)3.296 x J
Explanation:
For Sphere A:
mass 'Ma'= 47kg
xa= 0
For sphere B:
mass 'Mb'= 110kg
xb=3.4m
a)the gravitational potential energy is given by
= -GMaMb/ d
= - 6.67 x 
x 47 x 110/ 3.4 => -1.014x J
b) at d= 0.8m (3.4-2.6) and =-1.014x J
The sum of potential and kinetic energies must be conserved as the energy is conserved.
+ = 
+ 
As sphere starts from rest and sphere A is fixed at its place, therefore is zero
= +
The final potential energy is
= - GMaMb/d
Solving for ' '
= + GMaMb/d => -1.014x + 6.67 x x 47 x 110/ 0.8
= 3.296 x J
To determine the amount in grams of the iron, we need data on the density of iron. From literature, it has a value of <span>p=7.9 g/cm3. We simply multiply the volume to the density. We do as follows:
mass = 3.70 (7.9) = 29.23 g Fe
Hope this answers the question. Have a nice day.</span>
Answer:
2633.7 s
Explanation:
From the question,
Heat lost by the water heater = Heat gained by the water
Applying,
P = cm(t₂-t₁)/t.................. Equation 1
Where P = power of the heat, c = specific heat capacity of water, m = mass of water, t₁ = initial temperature, t₂ = final temperature, t = time
make t the subject of the equation
t = cm(t₂-t₁)/P.............. Equation 2
From the question,
Given: c = 4190 J/kgK, P = 3.5 kW = 3500 W, m = 40 kg, t₁ = 20°C, t₂ = 75°C
Substitute these values into equation 2
t = 4190×40(75-20)/3500
t = 9218000/3500
t = 2633.7 s
