Answer:
Ta có: P (
A
) P (
B
) = 0
,
12
. Vì P (
A
B
) = 0
,
2 ≠ 0
,
12 = P (
A
) P (
B
)
nên hai biến cố A và B không độc lập với nhau.
Step-by-step explanation:
Answer:
a. h = 60t − 4.9t²
b. 12.2 seconds
c. 183.7 meters
Step-by-step explanation:
a. Given:
y₀ = 0 m
v₀ = 60 m/s
a = -9.8 m/s²
y = y₀ + v₀ t + ½ at²
h = 0 m + (60 m/s) t + ½ (-9.8 m/s²) t²
h = 60t − 4.9t²
b. When the ball lands, h = 0.
0 = 60t − 4.9t²
0 = t (60 − 4.9t)
t = 0 or 12.2
The ball lands after 12.2 seconds.
c. The maximum height is at the vertex of the parabola.
t = -b / (2a)
t = -60 / (2 × -4.9)
t = 6.1 seconds
Alternatively, the maximum height is reached at half the time it takes to land.
t = 12.2 / 2
t = 6.1 seconds
After 6.1 seconds, the height reached is:
h = 60 (6.1) − 4.9 (6.1)²
h = 183.7 meters
Answer: Answer is b
Step-by-step explanation: The -2 represents the 0's
