Answer:
The speed is 20.8 m/s
Step-by-step explanation:
If a projectile ascends vertically, and after 3 seconds it reaches its maximum height, calculate the velocity that it carries to the middle of its downward trajectory
Let the maximum height is h and initial velocity is u.
From first equation of motion
v = u + at
0 = u - g x 3
u = 3 g.....(1)
Use third equation of motion

Let the speed at half the height is v'.

Answer:
Step-by-step explanation:
x² = 80² + 39²
x² = 6400 + 1521
x² = 7921
x = 89 inches
2:3:9......added together = 14
2/14 (500) = 1000/14 = 71.43
3/14 (500) = 1500/14 = 107.14
9/14 (500) = 4500/14 = 321.43
Answer:
a.b=[-1]
Step-by-step explanation:
This is a dot product of a and b
a.b =[6,-2,3].[2,5, -1] = [12-10-3] =[-1]