Simple Uniform Acceleration Question

In summary, a spaceship experiencing uniform acceleration from 65.0m/s to 162.0m/s in 10.0s moves 1135 meters.
  • #1
wwwwww
2
0

Homework Statement


Hello new user here. I'm utterly confused about uniform acceleration as my book does a very poor job (in my opinion) of explaining it. Could somebody please help me with this problem?

A spaceship far from any star or planet experiences uniform acceleration from 65.0m/s to 162.0m/s in 10.0s. How far does it move?


Homework Equations


Vf=Vi+at
d=Vit+.5at

The Attempt at a Solution


Well I tried to use the equation d=(Vf+Vi)/2 but I checked my answer with my teacher's answers and the answers were way different. I think it's because the problem uses uniform acceleration and not constant acceleration.
 
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  • #2
wwwwww said:

Homework Statement


Hello new user here. I'm utterly confused about uniform acceleration as my book does a very poor job (in my opinion) of explaining it. Could somebody please help me with this problem?

A spaceship far from any star or planet experiences uniform acceleration from 65.0m/s to 162.0m/s in 10.0s. How far does it move?


Homework Equations


Vf=Vi+at
d=Vit+.5at

The Attempt at a Solution


Well I tried to use the equation d=(Vf+Vi)/2 but I checked my answer with my teacher's answers and the answers were way different. I think it's because the problem uses uniform acceleration and not constant acceleration.

why not use the formula

d = 1/2(Vf+Vi).t

You seem to have forgotten there is a time factor in the formula.


Of course you could easily use the first two you quoted. Use the first to find the acceleration, then the second to use that acceleration to find the distance.

Final point: Uniform acceleration and Constant acceleration are the same thing.
 
  • #3
Uniform acceleration and constant acceleration are the same thing, it means that the acceleration remains at a fixed value throughout the course of motion.

The problem is giving you two velocities, since it is stated that the acceleration is constant, you must compute the acceleration from the two velocities.

So you need to ask yourself, what is acceleration? It is the change in velocity over a period of time. This should give you everything you need to answer the question. :]

EDIT: In physics, you shouldn't just try to throw a formula at things, but rather reason it through and make sense of the formulas.
 
  • #4
PeterO said:
why not use the formula

d = 1/2(Vf+Vi).t

You seem to have forgotten there is a time factor in the formula.


Of course you could easily use the first two you quoted. Use the first to find the acceleration, then the second to use that acceleration to find the distance.

Final point: Uniform acceleration and Constant acceleration are the same thing.

The formula that PeterO threw at this problem is simply another way to write
displacement = (average velocity) ✕ time .​
In the case of uniform acceleration, it's true that
(average velocity) = 1/2(Vf + Vi).​
 
  • #5
Oh thanks for the help. I got 1135 m, and the answer in the book is 1140 which I guess is close enough.
 
  • #6
Correct.

(Looks like they rounded off to 3 significant figures.)
 
  • #7
wwwwww said:
Oh thanks for the help. I got 1135 m, and the answer in the book is 1140 which I guess is close enough.

Your answer is correct. If that is the answer printed in the book it is wrong.
If they were trying to express to 3 significant figures it should have been 1.14 x 103 m or perhaps 1.14 km
 
  • #8
SammyS said:
The formula that PeterO threw at this problem is simply another way to write
displacement = (average velocity) ✕ time .​
In the case of uniform acceleration, it's true that
(average velocity) = 1/2(Vf + Vi).​

I didn't just throw in that equation.
There are 5 equations covering uniformly accelerated motion. wwwwww had listed 2 of them, I brought in a 3rd, more directly applicable, one and there are 2 more to go, but neither of them has direct application to this question.

Besides when wwwwww had listed d = (Vf + Vi)/2 it looked like a mis-quoting of the equation of motion I referred to.
 

What is simple uniform acceleration?

Simple uniform acceleration is the motion of an object at a constant rate of acceleration, meaning the object's velocity increases or decreases by the same amount over equal intervals of time.

How is simple uniform acceleration calculated?

Simple uniform acceleration is calculated by dividing the change in velocity by the change in time. The formula for simple uniform acceleration is a = (vf - vi) / t, where a is acceleration, vf is final velocity, vi is initial velocity, and t is time.

What is the difference between acceleration and velocity?

Acceleration is the rate at which an object's velocity changes, while velocity is the speed and direction of an object's motion. Acceleration can be positive or negative, depending on whether the velocity is increasing or decreasing.

How does air resistance affect simple uniform acceleration?

Air resistance can affect the acceleration of an object by creating a force that opposes its motion. This can cause the object to slow down and decrease its acceleration over time.

What are some real-life examples of simple uniform acceleration?

Some real-life examples of simple uniform acceleration include a car speeding up or slowing down on a straight road, a rollercoaster going up or down a hill, and a skydiver falling towards the ground without opening their parachute.

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