# How Accurate Are My Initial Velocity and Maximum Height Calculations?

• bwilhelm
In summary, the ball takes 1.80 seconds to reach its maximum height when thrown upwards. To find the initial velocity, use the formula v2 = v1 + at, where v2 is the final velocity (0 m/sec), a is the acceleration (-9.8 m/s^2), and t is the time (1.80 sec). To find the maximum height reached, use the formula s = v1*t + 1/2 at^2, where s is the displacement (31.74 m), v1 is the initial velocity, and t is the time (1.80 sec). To find the velocity 1.15 seconds after being thrown, use the formula v2 = v1 + at
bwilhelm
Am I anywhere near correct?

## Homework Statement

A ball is thrown and upward and reaches it's maximum height in 1.80 sec.

A. Find Initial Velocity
B. Find Max Height Reaced
C. Find Velocity 1.15 sec after being thrown.

## The Attempt at a Solution

A. .5(-9.8)*1.8^2= -15.87 m/sec
B. -15.87+.5(-9.8)*1.8^2 = 31.74m
C. .5(-9.8)1.15^2= -6.48 m/sec

No, not near correct. For part a, you used a displacement formula... so the result won't be a velocity...

Hint: for part a) use the fact that v2 = v1 + at. You know v2, a and t... use those to calculate v1.

For part b) you made a mistake with the formula... it should be s = v1*t + 1/2 at^2... you didn't multiply v1 by t... and also the v1 is wrong since part a was wrong...

For part c)... here again you use a displacement formula... so the result that comes out will be displacement not a velocity... 1/2 at^2 is a distance not a velocity.

Your calculations for parts A, B, and C appear to be correct. However, without any context or additional information, it is difficult to determine if your answers are correct. It would be helpful to know what type of problem this is (e.g. physics, kinematics, etc.) and if there are any given values for initial velocity, acceleration, or other relevant variables. Additionally, it is important to label your units in your calculations to ensure accuracy. Overall, it seems like you are on the right track but it would be beneficial to provide more context and information for a more accurate response.

## 1. What is initial velocity?

Initial velocity, also known as initial speed, is the rate at which an object is moving at the beginning of a specific time period. It is typically represented by the symbol "v0" in equations.

## 2. How is initial velocity calculated?

Initial velocity is calculated by dividing the change in distance (Δx) by the change in time (Δt). This can be represented by the equation v0 = Δx/Δt. It can also be calculated using the equation v0 = u + at, where u is initial velocity, a is acceleration, and t is time.

## 3. What are the units of initial velocity?

The units of initial velocity depend on the units used to measure distance and time. However, the most common units are meters per second (m/s) or feet per second (ft/s).

## 4. Why is initial velocity important in science?

Initial velocity is important in science because it helps us understand the motion of objects. By knowing the initial velocity, we can calculate the final velocity and determine how far an object will travel over a certain period of time. It is also a key component in many equations and laws, such as Newton's Second Law of Motion.

## 5. Can initial velocity be negative?

Yes, initial velocity can be negative. A negative initial velocity indicates that the object is moving in the opposite direction of the positive direction. For example, if an object is thrown downwards, its initial velocity would be negative because it is moving in the negative direction (downwards) relative to its starting point.

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