Acceleration plus velocity question? ?

In summary, Kirk and Andrew are 29.0 m apart in a hallway. Andrew accelerates towards Kirk at a constant rate of 0.18m/s^2, while Kirk walks towards Andrew at a constant velocity of 3.0m/s. By setting their distance formulas equal to each other, it can be determined that they will high five after a time t, where Andrew's distance from the starting point is equal to 29 - 1/2at^2.
  • #1
bobsagget
18
0
Kirk and andrew are at opposite ends of a hallway stretching 29.0 m. Andrew accelerates from REST towards kirk at a constant rate of 0.18m/s^2. K irk walks towards andrew at a constant veloctiy of 3.0m/s. HOw much time elaspes before kirk and andrew high five".

kirk
v1= 3.0 m/s
acc= 0 m/s^2
distance (K)=?
time passed =?

andrew
v1= 0 m/s
time passed =?
acc= 0.18 m/s^2
distance= 29m -d(k)

i then got an equation for kirk which was delta d= Vavg/ time

and andrews was d=v1(delta)T+1/2(acc)(time^2)
^ ^ ^
cancels because v1=0

then i subbed d=29m-d(K) and got

29-D(of kirk) = 1/2(acc)(time^2)

i don't know what to do after? any help? or if I am doing it right at all please help!
 
Physics news on Phys.org
  • #2
bobsagget said:
Kirk and andrew are at opposite ends of a hallway stretching 29.0 m. Andrew accelerates from REST towards kirk at a constant rate of 0.18m/s^2. K irk walks towards andrew at a constant veloctiy of 3.0m/s. HOw much time elaspes before kirk and andrew high five".

kirk
v1= 3.0 m/s
acc= 0 m/s^2
distance (K)=?
time passed =?

andrew
v1= 0 m/s
time passed =?
acc= 0.18 m/s^2
distance= 29m -d(k)

i then got an equation for kirk which was delta d= Vavg/ time

and andrews was d=v1(delta)T+1/2(acc)(time^2)
^ ^ ^
cancels because v1=0

then i subbed d=29m-d(K) and got

29-D(of kirk) = 1/2(acc)(time^2)

i don't know what to do after? any help? or if I am doing it right at all please help!

Good set up. You have the right distance formulas for both. Solve andrew's distance formula in terms of D then set both distance formulas equal to each other and you should find a time t that they intersect or meet up.

(You will find that Andrew's distance = 29 - 1/2at^2)
 
  • #3
oooo ok thanks, now i understand the rest :smile:
 

1. What is acceleration?

Acceleration is the rate of change of an object's velocity over time. It is a measure of how quickly an object's speed or direction changes.

2. How is acceleration calculated?

Acceleration can be calculated by dividing the change in an object's velocity by the change in time. It is expressed in units of meters per second squared (m/s^2).

3. What is the difference between acceleration and velocity?

Velocity is a measure of an object's speed and direction, while acceleration is a measure of how an object's velocity changes over time. In other words, velocity tells us how fast an object is moving, while acceleration tells us how quickly that object is changing its speed or direction.

4. What is positive and negative acceleration?

Positive acceleration occurs when an object's velocity is increasing, while negative acceleration (also known as deceleration) occurs when an object's velocity is decreasing. Positive acceleration is represented by a positive value, while negative acceleration is represented by a negative value.

5. How does acceleration affect an object's motion?

Acceleration can change an object's motion in a number of ways. If an object is accelerating in the same direction as its velocity, it will speed up. If an object is accelerating in the opposite direction of its velocity, it will slow down. Acceleration can also cause an object to change direction or come to a stop.

Similar threads

  • Introductory Physics Homework Help
Replies
3
Views
788
  • Introductory Physics Homework Help
Replies
17
Views
2K
  • Introductory Physics Homework Help
Replies
5
Views
2K
  • Introductory Physics Homework Help
Replies
8
Views
1K
  • Introductory Physics Homework Help
Replies
21
Views
178
  • Introductory Physics Homework Help
Replies
1
Views
2K
  • Introductory Physics Homework Help
Replies
6
Views
962
  • Introductory Physics Homework Help
Replies
3
Views
1K
  • Introductory Physics Homework Help
Replies
16
Views
1K
  • Introductory Physics Homework Help
Replies
1
Views
1K
Back
Top