The so-called "velocity-time" graph is actually a "speed-time" graph. At any point
on it, the 'x'-coordinate is a time, and the 'y'-coordinate is the speed at that time.
'Velocity' is a speed AND a direction. Without a direction, you do not have a velocity,
and these graphs never show the direction of the motion. It seems to me that it would be
pretty tough to draw a graph that shows the direction of motion at every instant of time,
so my take is that you'll never see a true "velocity-time" graph.
At best, it would need a second line on it, whose 'y'-coordinate referred to a second
axis, calibrated in angle and representing the 'bearing' or 'heading' of the motion at
each instant. The graph of uniform circular motion, for example, would have a straight
horizontal line for speed, and a 'sawtooth' wave for direction.
Answer:
Explanation:
We shall apply here Doppler's effect in optics . The formula is as follows

Δλ is change in wavelength , λ is original wavelength , v is velocity and c is velocity of light
Δλ = 685 - 590 = 95 nm
λ = 685
95 / 685 = v / 3 x 10⁸
v = .416 x 10⁸ m / s
= 4.16 x 10⁷ m /s
Answer:
False
Explanation:
Please see the attached file