Answer: 1.95
Explanation:
You should start off from the decay formula and solve for τ:
Apply inverse logarithmic function:
The final form will be:
Inputing values for I, IO, and t:
Answer:
1.84 kJ (kilojoules)
Explanation:
A specific heat of 0.46 J/g Cº means that it takes 0.46 Joules of energy to raise the temperature of 1 gram of iron by 1 Cº.
If we want to heat 50 g of iron from 20° C to 100° C, we can make the following calculation:
Heat = (specific heat)*(mass)*(temp change)
Heat = (0.46 J/g Cº)*(50g)*(100° C - 20° C)
[Note how the units cancel to yield just Joules]
Heat = 1840 Joules, or 1.84 kJ
[Note that the number is positive: Energy is added to the system. If we used cold iron to cool 50g of 100° C water, the temperature change would be (Final - Initial) or (20° C - 100° C). The number is -1.84 kJ: the negative means heat was removed from the system (the iron).
Answer:
3/5 v
Explanation:
The computation of speed will the alpha particle have after the collision is shown below:-
In a perfectly elastic the kinetic energy and collision the momentum are considered.
The velocity of the particles defines the below equation:
As we know that
Here, we consider A is the alpha particle and B is the proton and now by the above values we can solve the equation which is below:-
Therefore the correct answer is 
Answer:
F = 326.7 N
Explanation:
given data
mass m = 200 kg
distance d = 2 m
length L = 12 m
solution
we know force exerted by the weight of the rock that is
W = m × g ..............1
W = 200 × 9.8
W = 1960 N
and
equilibrium the sum of the moment about that is
∑Mf = F(cos∅) L - W (cos∅) d = 0
here ∅ is very small so cos∅ L = L and cos∅ d = D
so F × L - W × d = 0 .................2
put here value
F × 12 - 1960 × 2 = 0
solve it we get
F = 326.7 N
