Answer : The time passed in years is 20.7 years.
Explanation :
Half-life = 28.1 years
First we have to calculate the rate constant, we use the formula :



Now we have to calculate the time passed.
Expression for rate law for first order kinetics is given by:

where,
k = rate constant = 
t = time passed by the sample = ?
a = initial amount of the reactant = 1.00 g
a - x = amount left after decay process = 0.600 g
Now put all the given values in above equation, we get


Therefore, the time passed in years is 20.7 years.
The distance is 17 and the displacement is 1
Answer:
has units of distance
has units of distance over time
has units of distance over 
has units of distance over 
Explanation:
Since the expression for the distance is:

then:
has units of distance
has units of distance over time
has units of distance over 
has units of distance over 
because we are supposed to be able to add all of the terms and get a distance. So the products on each term that contains factors of time (t) should be cancelling those time units with units in the denominator of the multiplicative constant s that accompany them.
Answer:
a. dW = ∫pEsinθdθ b. W = p.E
Explanation:
a. We know torque τ = p × E = pEsinθ where θ is the angle between p and E
Let the torque τ rotate the dipole by an amount dθ. So, the workdone dW = ∫τdθ = ∫pEsinθdθ
b. So, the total work done is gotten by integrating from 90 to θ. So,
W = ∫₉₀⁰dW
= ∫₉₀⁰pEsinθdθ
= pE∫₉₀⁰sinθdθ
= pE(cosθ - cos90)
=pEcosθ
= p.E
Answer:
Distance covered is equal to all the distance traveled.
So for example, if you go from A to B, and then from B to C, the total distance covered is AB + BC.
Displacement is equal to the difference between the final position and the initial position.
So if we go from A to B, the displacement is simply the line AB.
While if we go from A to B, and then from B to C, the displacement will be a segment that directly connects A and C, such that:
displacement = √( (AB)^2 + (BC)^2)
Now, if we want to find the points such that the magnitude of the distance covered is equal to the magnitude of the displacement, we need to look at the pairs that are directly connected by a straight line.
Those are:
A to B ( or B to A)
B to C (or C to B)
C to D (or D to C)