Explanation:
Given that, the height of the tide measured at a seaside community varies according to the number of hours t after midnight. The height is given by the equation as :
When the tide first be at 6 ft, put h = 6 ft in above equation as :
On solving the above equation to find the value of t. It is equal to :
t = 3.551 seconds
or
t = 8.449 seconds
So, the tide of 6 ft is at 3.551 seconds and 8.449 seconds. Hence, this is the required solution.
Answer:
d. Both A & C
Explanation:
- The velocity of the ball is a vector, whose magnitude indicates its rate of change of position, and it has a direction. In this case, the ball is moving upward, therefore the direction of motion is upward, so the direction of the velocity is upward as well.
- The acceleration of the ball is a vector, whose magnitude indicates the rate of change of the velocity. The direction of the acceleration is:
-- positive if the the magnitude of the velocity is increasing
-- negative if the magnitude of the velocity is decreasing
For a ball thrown upward, the acceleration is given by the acceleration of gravity, . This acceleration points downward, and it is constant during the entire motion. In particular, it does not change direction, as it is always directed downward. Therefore, the acceleration of the ball is downward.
So, the correct answer is
d.Both A & C
Since A and C are both true:
a.The velocity vector is directed upward.
c.The acceleration is directed downward.