A ball is launched from ground level at 30 m/s at an angle of 35° above the horizontal. how far does it go before it is at ground level again

Explanation:

Ignoring air resistance

Initial vertical velocity is 30sin35 = 17.2 m/s

Gravity reduces this velocity to zero in a time of

t = v/g =17.2 / 9.8 = 1.755 s

it takes the same time to come back down to ground level for a total flight time of 2(1.755) = 3.51 s

The horizontal velocity is 30cos35 = 24.57 m/s

the distance traveled horizontally is

d = vt = 24.57(3.51) = 86.298... = 86 m

when insulating materials rub against each other, they may become electrically charged . electrons , which are negatively charged, may be 'rubbed off' one material and on to the other. the material that gains electrons becomes negatively charged. the material that loses electrons is left with a positive charge.

d. platinum would have the greatest temperature increase because it has the lowest specific heat.