8. a train rolls at a constant speed of 10 m/s across a horizontal track. a child standing on the flatbed of the
train throws a ball so that it appears to move straight up to an observer standing next to the track.
a. what is the horizontal speed of the ball relative to the observer?
b. what is the horizontal speed of the ball relative to the train?
c. if the ball is also thrown upward with a speed of 20 m/s, what is the overall initial speed of the ball
relative to the train?

force required to detach it is given by

charges are taken to be fundamental charge

now we have

so above is the minimum distance at which it will detach

the design of a ski jumping suit involves a trade-off between giving the skiers lift to get higher jumps and ensuring the skier does not face a lot of drag before the jump itself. an expansive suit may to lift the skier higher, but at the same time, it will also increase the air resistance. higher air resistance as the skier goes down the slope limits the speed of the jump. a big suit also increases the risk of losing balance or control, especially if there's a strong gust of wind. while technologically enhanced suits a lot, clothing is not the only factor in a ski jumper’s success. gathering speed while skiing down the slope, ensuring good speed on the ramp, and maintaining good body posture and form in the air all contribute to a ski jumper's success.