A rock is thrown vertically upward at an initial velocity of 70 m/s. What is the approximate acceleration of the rock when it reaches its maximum height (assume upward is the positive y direction)?

Zero.

Explanation:

Given that a rock is thrown vertically upward at an initial velocity of 70 m/s. What is the approximate acceleration of the rock when it reaches its maximum height

(assume upward is the positive y direction)?

Since the reached the maximum height, the final velocity V will be equal to zero.

Using the first equation of motion to find the time.

And since it is a vertical direction, and not horizontal, the acceleration a will be equal to zero.

f=ma newton's second law 7x8=56n

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