Question

Please help me out
please show solvings​

Answer 1

5) The approximate height is about 80 m. Choice (c)

6) The stone takes about 3 seconds to rise to its maximum height

Step-by-step explanation:

Free Fall Motion

A free-falling object falls under the sole influence of gravity. Any object that is being acted upon only by the force of gravity is said to be in a state of free fall.

If an object is dropped from rest in a free-falling motion, it falls with a constant acceleration called the gravitational acceleration, which value is
`g = 9.8 m/s^2`.

The distance traveled by a dropped object is:

`\displaystyle y=(gt^2)/(2)`

Question 5

Given the stone reaches the ground in t=4 seconds, the height of the tower is:

`\displaystyle y=(9.8*4^2)/(2)=78.4\ m`

The approximate height is about 80 m. Choice (c)

Question 6

Vertical Motion

The vertical motion of an object is controlled by the force of gravity. This means that there is a non-zero net force acting on the object that makes it accelerate downwards.

If the object is thrown upwards at speed vo, its speed at time t is:

`v_f=v_o-g.t`

The stone reaches its maximum height when the final speed is zero, thus:

`v_o-g.t=0`

Solving for t:

`\displaystyle t=(v_o)/(g)`

The stone is thrown vertically upwards with vo=30 m/s, thus:

`\displaystyle t=(30)/(9.8)`

`t=3.06\ s`

`t\approx 3\ s`

The stone takes about 3 seconds to rise to its maximum height