Скачать или смотреть how to calculate your reaction time a science with bobert video short

2) You can take advantage of the fact that all objects fall at the same rate to calculate your reaction time. Place your fingers one inch apart and have someone hold a ruler between your fingers. Catch the ruler with your fingers as soon as you see it falling. Then look at the ruler and measure how far the ruler fell in inches. You can then use the below equation to calculate your reaction time in seconds! (showing video of dr smith and bobert’s paw can be dropping ruler…)


t = square root 2d/g where g = 386 in/s2 and d = the distance the ruler fell 1.5 inches. For exmple Dr. Smith's ruler fell 1.5" so his reaction time is........0.09s!



Projectile motion
Did you know that a horizontally moving object falls at the same rate as a dropped object as long as air resistance is the same for both objects? This is a free fall device. Dr. Smith is going to place the device high on top of a ladder. When he releases the lever on the device……one steel ball will shoot straight out and the other will be dropped. Which steel ball do you think will strike the ground first?
(a) the ball dropped will strike the ground first
(b) the ball shooting straight out will strike the ground first
(c) the steel balls will strike the ground at the same time






review
forces end up being either a push or a pull on an object
if all the forces acting on an object do not cancel out the object will accelerate in the direction of the overall unbalanced force
falling objects are weightless and fall to the ground at the same rate (assuming air resistance is the same)
horizontally moving objects fall at the same rate as dropped objects when air resistance is the same