Answer:

Explanation:
First we have to find the time required for train to travel 60 meters and impact the car, this is an uniform linear motion:

The reaction time of the driver before starting to accelerate was 0.50 seconds. So, remaining time for driver is 1.5 seconds.
Now, we have to calculate the distance traveled for the driver in this 0.5 seconds before he start to accelerate. Again, is an uniform linear motion:

The driver cover 10 meters in this 0.5 seconds. So, the remaining distance to be cover in 1.5 seconds by the driver are 35 meters. We calculate the minimum acceleration required by the car in order to cross the tracks before the train arrive, Since this is an uniformly accelerated motion, we use the following equation:

Use pythagorean theorem

to find the opposite side, which is 7.3
so then you can just use inverse sinA=7.3/10 which equals 46.9 degrees
Answer:
a)
, b) 
Explanation:
a) The equation for vertical velocity is obtained by deriving the function with respect to time:

The velocities at given instants are, respectivelly:


The visible spectrum ranges from 390 nm to 700 nm. the visible spectrum consist of the red ( 620 - 750 nm ) , orange ( 590 - 620 nm ) , yellow ( 570 - 590 nm ) , green ( 495 - 570 nm ) , blue ( 450 - 495 nm ) and violet ( 380 - 450 nm ) so the wave length 449 nm will produce a violet color
Electron volts...........