By
vector addition.
In fact, velocity is a vector, with a magnitude intensity, a direction and a verse, so we can't simply do an algebraic sum of the two (or more velocities).
First we need to decompose each velocity on both x- and y-axis (if we are on a 2D-plane), then we should do the algebraic sum of all the components on the x- axis and of all the components on the y-axis, to find the resultants on x- and y-axis. And finally, the magnitude of the resultant will be given by

where Rx and Rx are the resultants on x- and y-axis. The direction of the resultant will be given by

where

is its direction with respect to the x-axis.
Answer:
The velocity will be "76.8 m/s".
Explanation:
The given values are:
Acceleration,
a = 2.4 m/s²
Time,
t = 32 seconds
By equation of motion,
⇒ 
On substituting the values, we get
⇒ 
⇒ 
⇒ 
Answer:
Double helix
Explanation:
The Double helix is a DNA molecule. The two strands around the Double Helix is called the twisted ladder.
Answer is D.
Speed:
Use relative speed to simplify the situation. Since the trains are moving in opposite directions, you can add the speeds and pretend the first train is stationary (moving at 0m/s) and the second train is moving at 50m/s.
Distance:
The front of the second train needs to travel 120m to get from the front to the back of the first train. When the front of the second train is at the back of the first train, the back of the second train is still 10m in front of the first train. The back therefore has to travel 130m to clear the first train. The total distance over which the trains are overlapping in this scenario is therefore 120 + 130 = 250m.
You have speed and you have distance so now just calculate time:
v = d / t
50 = 250 / t
t = 5s