acceleration vocabulary\nuse the following to fill in the blanks\n|acceleration|direction|meters per second…

acceleration vocabulary\nuse the following to fill in the blanks\n|acceleration|direction|meters per second squared (m/s²)|slowing down|\n|----|----|----|----|\n|$a = \\frac{v_f - v_i}{t}$|divide|meters per second (m/s)|subtract|\n|velocity|increasing speed|positive|time interval|\n| |negative|seconds|change|\nspeed is the rate of motion of an object. __________________ describes an object’s speed and direction. the velocity of an object can __________________ even if the speed of the object remains constant. this would occur if the __________________ of the object’s motion changes.\nthe rate of change of velocity is called __________________ . the size of an acceleration depends on both the change in velocity and the __________________ of the change. to calculate acceleration, __________________ the change in velocity by the time interval. to find the change in velocity, __________________ the initial velocity (vᵢ) from the final velocity (vբ). the equation for average acceleration is __________________ . final velocity will be less than initial velocity if an object is __________________ , and acceleration will have a __________________ value. final velocity will be greater than initial velocity if an object is __________________ , and acceleration will have a __________________ value.\nthe units for velocity are __________________ . the unit for time is __________________ . therefore, the units for acceleration are __________________ .\nsolve the following (show your work):\n1. maddix drives a car that is uniformly accelerated at the rate of 2.5m/s² for 12s. if the original speed of the car is 8.0m/s, what is its final velocity?\n2. jesse is in a car whose velocity increases from rest to 14 m/s, in 3.5 sec. what is its acceleration? what is its acceleration if it next slows down to 7 m/s, in 2 sec?\n3. emily is in a car that is moving at 16.67 m/s when it begins to decelerate at 1.5m/s². how long does it take for it to slow down to 8.7 m/s?
Answer
Explanation:
Step1: Identify the formula for final - velocity
The formula for final velocity in uniformly - accelerated motion is $v = v_0+at$, where $v$ is the final velocity, $v_0$ is the initial velocity, $a$ is the acceleration, and $t$ is the time.
Step2: Substitute the given values into the formula for Maddix's car
Given $v_0 = 8.0m/s$, $a = 2.5m/s^2$, and $t = 12s$. $v=8.0 + 2.5\times12$ $v=8.0+30$ $v = 38m/s$
Step3: Identify the formula for acceleration
The formula for acceleration is $a=\frac{v - v_0}{t}$, where $v$ is the final velocity, $v_0$ is the initial velocity, and $t$ is the time.
Step4: Calculate the acceleration for Jesse's car when accelerating
Given $v_0 = 0m/s$ (starts from rest), $v = 14m/s$, and $t = 3.5s$. $a=\frac{14 - 0}{3.5}=\frac{14}{3.5}=4m/s^2$
Step5: Calculate the acceleration for Jesse's car when decelerating
Given $v_0 = 14m/s$, $v = 7m/s$, and $t = 2s$. $a=\frac{7 - 14}{2}=\frac{- 7}{2}=-3.5m/s^2$
Step6: Rearrange the acceleration formula to solve for time when decelerating
The formula $a=\frac{v - v_0}{t}$ can be rearranged to $t=\frac{v - v_0}{a}$. For Emily's car, $v_0 = 16.67m/s$, $v = 8.7m/s$, and $a=-1.5m/s^2$ (negative because it's decelerating). $t=\frac{8.7 - 16.67}{-1.5}=\frac{-7.97}{-1.5}\approx5.31s$
Answer:
- The final velocity of Maddix's car is $38m/s$.
- The acceleration of Jesse's car when accelerating is $4m/s^2$ and when decelerating is $-3.5m/s^2$.
- It takes approximately $5.31s$ for Emily's car to slow down.