lim said:Homework Statement
At highway speeds, a particular automobile is capable of an acceleration of about 1.57 m/s2. At this rate, how long does it take to accelerate from 72.0 km/hr to 100.0 km/hr?
Homework Equations
I was given: vf = vi + at
The Attempt at a Solution
Simplifying the velocities I got 28 = 1.57a
and a= 17.83 s.
To calculate the time it takes with changing acceleration, you need to use the formula t = vf - vi / a, where t is the time, vf is the final velocity, vi is the initial velocity, and a is the acceleration. This formula is derived from the basic kinematic equation, vf = vi + at, where t is the time.
Changing acceleration is when the rate of change of velocity is not constant. This means that the acceleration is either increasing or decreasing over time, leading to a changing acceleration value.
To determine the final velocity when the acceleration is changing, you can use the equation vf = vi + at, where vf is the final velocity, vi is the initial velocity, a is the acceleration, and t is the time. Alternatively, you can use the formula vf = √(vi^2 + 2ad), where d is the displacement.
One example of a scenario with changing acceleration is a car that is accelerating from 0 to 60 mph in 10 seconds. In this scenario, the acceleration is changing because the car is going from a standstill to a constant velocity of 60 mph. The acceleration is increasing over time until it reaches 60 mph, after which it remains constant.
Changing acceleration can affect the time it takes to reach a certain velocity because the acceleration is not constant. If the acceleration is increasing, it will take less time to reach the desired velocity compared to when the acceleration is decreasing. This is because the rate of change of velocity is higher when the acceleration is increasing, leading to a shorter time to reach the desired velocity.