Answer:
C. weak cohesive forces exist between its molecules.
Explanation:
This is because water has less intermolecular forces than solids, but more than gases. Also their cohesive forces is low.
Answer:
98 m √
Explanation:
How about s = Vo * t + ½at² ?
s = h = Vo * 2s - 4.9m/s² * (2s)² = 2Vo - 19.6
and
h = Vo * 10s - 4.9m/s² * (10s)² = 10Vo - 490
Subtract 2nd from first:
0 = -8Vo + 470.4
Vo = 58.8 m/s
h = 58.8m/s * 2s - 4.9m/s² * (2s)² = 98 m
Split the operation in two parts. Part A) constant acceleration 58.8m/s^2, Part B) free fall.
Part A)
Height reached, y = a*[t^2] / 2 = 58.8 m/s^2 * [7.00 s]^2 / 2 = 1440.6 m
Now you need the final speed to use it as initial speed of the next part.
Vf = Vo + at = 0 + 58.8m/s^2 * 7.00 s = 411.6 m/s
Part B) Free fall
Maximum height, y max ==> Vf = 0
Vf = Vo - gt ==> t = [Vo - Vf]/g = 411.6 m/s / 9.8 m/s^2 = 42 s
ymax = yo + Vo*t - g[t^2] / 2
ymax = 1440.6 m + 411.6m/s * 42 s - 9.8m/s^2 * [42s]^2 /2
ymax = 1440.6 m + 17287.2m - 8643.6m = 10084.2 m
Answer: ymax = 10084.2m
Newton's Second law of motion:
Force = (mass) x (acceleration)
Force = (15kg) x (8m/s²) = 120 kg-m/s² = 120 newtons
1140x9.8x2.4= 26,812.8 significant figures Make it 27,000
