Object in free fall - Velocity

[mybrohshi5]

Homework Statement

An object is in free fall at the surface of the Earth. In a certain 1.0 second time interval, the average velocity of the object is measured to be 2.0 m/s downward.

What was the velocity of the object at the beginning of the 1.0 second interval?

Homework Equations

V_avg = v_i + v_f / 2

The Attempt at a Solution

I came across this as i am studying for my physics final.

The answer is 2.9 m/s upward.

I am not sure how to get this because i cannot think of the right equation to use to get me to the correct answer.

Any help or hints would be greatly appreciated. Thank you

 

[PhanthomJay]

You have the first equation, with 2 unknowns.
You need another equation of motion to solve for vi and vf.
List what is known and unknown.
Watch your plus and minus signs.

 

[AC130Nav]

Homework Statement

An object is in free fall at the surface of the Earth. In a certain 1.0 second time interval, the average velocity of the object is measured to be 2.0 m/s downward.

What was the velocity of the object at the beginning of the 1.0 second interval?

Homework Equations

V_avg = v_i + v_f / 2

The Attempt at a Solution

I came across this as i am studying for my physics final.

The answer is 2.9 m/s upward.

I am not sure how to get this because i cannot think of the right equation to use to get me to the correct answer.

Any help or hints would be greatly appreciated. Thank you

It seems to me you need a starting point. The problem as stated seems insoluable--or having infinite solutions, if you prefer.

 

[mybrohshi5]

You have the first equation, with 2 unknowns.
You need another equation of motion to solve for vi and vf.
List what is known and unknown.
Watch your plus and minus signs.

Thank you Jay. I think i got it now using the other equation: vf = vi + at

 

[rdl]

.

As a scientist, it is important to understand the concept of free fall and its relationship with velocity. In free fall, an object is only under the influence of gravity and no other forces. This means that the object's acceleration is constant and equal to the acceleration due to gravity, which is approximately 9.8 m/s^2 downward at the surface of the Earth.

In this scenario, the object's initial velocity (vi) is unknown, but we do know its average velocity (Vavg) and the time interval (1.0 second). To solve for vi, we can use the equation Vavg = vi + vf / 2, where vf is the final velocity. Since the object is in free fall, vf can be calculated using the equation vf = vi + at, where a is the acceleration due to gravity and t is the time interval.

Substituting this into the first equation, we get Vavg = vi + (vi + at) / 2. Solving for vi, we get vi = (2Vavg - at) / 2. Plugging in the given values, we get vi = (2(2.0 m/s) - (9.8 m/s^2)(1.0 s)) / 2 = 0.2 m/s upward.

Therefore, the object's initial velocity at the beginning of the 1.0 second interval was 0.2 m/s upward. This makes sense since the object is initially at rest and then accelerates downwards due to gravity. I hope this explanation helps you understand the concept better. Good luck on your final exam!