The answer is A.
Explanation:
We know that the average acceleration a for an interval of time Δt is expressed as:
a = Δv
Δt
where Δv is the change in velocity that occurs during Δt.
e formula for the instantaneous acceleration a is almost the same, except that we need to indicate that we're interested in knowing what the ratio of Δv to Δt approaches as Δt approaches zero.
We can indicate that by using the limit notation.
So, the formula for the instantaneous acceleration is:
a = lim Δv
Δt→0 Δt
Answer:
Explanation:
The direction of propagation of electromagnetic wave
is given by the direction of vector E x B where E is electrical field , B is magnetic field .
Given Electric field = E i because it is along x axis
Magnetic field = Bj because it is along y axis
E x B = Ei x Bj
= EB k .
so direction of E x B is along k direction or z - axis so wave is propagating along z - axis .
The relationship between speed of a wave w, frequency f and wavelength

is

For the wave of our problem,

and f=60 Hz, so its speed is
Answer:T=1316.21 N
Explanation:
The tension has two components: Vertical and Horizontal. The
horizontal component is ma, the vertical component is mg. Using
Pythagoras theorem, we can find the tension as:
T=((ma)^2 (mg)^2)^(1/2)
So
T=((129*2.84)^2 (129*9.8)^2)^(1/2)
T=1316.21 N