<span>if we assume the origin is at the dropping point and the object is merely dropped and not thrown up or down then y0 = 0 and v0 = 0. The equation reduces to </span>
<span>y = 0 + 0t + ½gt² </span>
<span>y = ½gt² </span>
<span>t = √(2y/g) </span>
<span>in the ft - lb - s system </span>
<span>y = -100 ft </span>
<span>g = -32.2 ft / s² </span>
<span>t = √(2y/g) </span>
<span>t = √(2(-100) / (-32.2)) </span>
<span>t = 2.5 s</span>
Answer:
Explanation:
Mass of ice m = 500g = .5 kg
Heat required to raise the temperature of ice by 10 degree
= mass of ice x specific heat of ice x change in temperature
= .5 x 2093 x 10 J
10465 J
Heat required to melt the ice
= mass of ice x latent heat
0.5 x 334 x 10³ J
167000 J
Heat required to raise its temperature to 18 degree
= mass x specific heat of water x rise in temperature
= .5 x 4182 x 18
=37638 J
Total heat
=10465 +167000+ 37638
=215103 J
Answer: Physical changes in nature could then be erosion in a mountain, the melting of snow, and a river freezing over from the cold. Since none of these changes affect the chemical composition of the mountain, the snow, or the river, they are physical changes.
Explanation:
<span>49N is the force needed to give a .25 kg arrow an acceleration of 196m/s2. F =ma ⇒ =( 0.25kg)(196m/s2) = 49N if the arrow is shot horizontally where the applied force is entirely in the x-direction.</span>
