Answer:

Explanation:
With a initial velocity is zero, kinematics equation is:


Answer:
When white light strikes a colored opaque object, some colors of light are absorbed and some are reflected. ... Some of the colors are absorbed and some are reflected. When white light shines on a white object, all colors are reflected. When white light strikes a black object, all colors are absorbed.
Explanation:
Answer:
t = 3.414 s
s = 23.3 m
Explanation:
Let t be the total time of motion
Let s be the total distance of motion
s - s/2 = ½at² - ½a(t - 1²) = ½a(t² - (t - 1)²)
s/2 = ½a(t² - (t² - 2t + 1)) = ½a(t² - t² + 2t - 1)
s = a(2t - 1)
s = 4(2t - 1)
s = 8t - 4
8t - 4 = ½4t²
8t - 4 = 2t²
0 = 2t² - 8t + 4
0 = t² - 4t + 2
t = (4 ±√(4² - 4(1)(2))) / 2 = (4 ± √8)/2 = 2 ± √2
t = 3.414 s
or
t = 0.5857... s which we ignore because it does not have a full last second.
s = ½(4)3.414² = 23.3137... 23.3 m
Answer:
a. 45 N. / b. 0.08 m/s^2. / c. 102 N
F = ma
F = 15(3)
F = 45 newtons
F/m = a
20/250 = a
0.08 m/s^2 = a
R = ma
R =1.5(68)
102 N