If the elevator was stationary, the scale would read exactly the weight of the person:

However, the elevator is moving with an acceleration a, so the scale reads a new value of the weight, which we call W'. Newton's second law becomes

where a' is actually the total acceleration of the person, so it's the sum of the acceleraion of the elevator and of the gravitational acceleration:

Taking the direction of g (downward) as the positive direction, we can find the value of a:


So, the acceleration of the elevator is

, with same sign of g, so it's directed downward as well.
The answer to this question is two violins, a viola and a cello
The string quartet is one of the earliest form of musical ensembles in history. This form of ensembles was brought to recognition by the Austrian composer Joseph Haydn<span>, with his works in the 1750s establishing the genre and this form is still considered one of the hardest ensembles because each player has to cover a lot of parts within a session.</span>
the most appropriate answer is A !! our mind automatically connects everything and thus make a story that we don't even familiar with in actual !!
A) We differentiate the expression for velocity to obtain an expression for acceleration:
v(t) = 1 - sin(2πt)
dv/dt = -2πcos(2πt)
a = -2πcos(2πt)
b) Any value of t can be plugged in as long as it is greater than or equal to 0.
c) we integrate the expression of velocity to find an expression for displacement:
∫v(t) dt = ∫ 1 - sin(2πt) dt
x(t) = t + cos(2πt)/2π + c
x(0) = 0
0 = = + cos(0)/2π + c
c = -1/2π
x(t) = t + cos(2πt)/2π -1/2π