Kinematics Problem: Sprinter Acceleration and Velocity

In summary: After that, you only have to use the equations of motion to find the required parameters. In summary, a sprinter starts from rest and accelerates with a constant acceleration for the first 2 seconds, covering 10 meters. Then, the remaining 90 meters are run with the same velocity. The sprinter's constant acceleration during the first 2 seconds is 5 m/s. The case here is uniformly accelerated motion. The total time needed to run the full 100 meters is 6.32 seconds.
  • #1
tdreceiver17
10
0
Ok so I have this problem which is most likely easy to all of you. The problem says that the first 10 meters of the 100 meter are covered in the first 2 seconds by a sprinter who starts from rest and accelerates with a constant acceleration. The remaining 90 meters are run with the same velocity the sprinter had after 2 seconds.
a. Determine the sprinters constant acceleration during the first 2 seconds. I got 5 m/s

b. Determine the sprinters velocity after 2 seconds have elapsed. I couldn't decide on 5 m/s^2 or 10 m/s^2 because i used Vf=Vo+at and V=d/t and it gave me those two different answers.

c. Determine the total time needed to run the full 100 meters. I got 6.32s which is unrealistic.





Please help me out I'm a little rusty just starting physics two and would love for you guys to solve and compare answers. Thank you!
 
Physics news on Phys.org
  • #2
tdreceiver17 said:
I got 5 m/s

What are the units of acceleration?

b. Determine the sprinters velocity after 2 seconds have elapsed. I couldn't decide on 5 m/s^2 or 10 m/s^2 because i used Vf=Vo+at and V=d/t and it gave me those two different answers.

One of these formulas applies to uniformly accelerated motion. Another to motion with constant velocity. What is the case here? And, again, watch out for correct units.

c. Determine the total time needed to run the full 100 meters. I got 6.32s which is unrealistic.

Explain how you got that.
 
  • #3
tdreceiver17 said:
Ok so I have this problem which is most likely easy to all of you. The problem says that the first 10 meters of the 100 meter are covered in the first 2 seconds by a sprinter who starts from rest and accelerates with a constant acceleration. The remaining 90 meters are run with the same velocity the sprinter had after 2 seconds.
a. Determine the sprinters constant acceleration during the first 2 seconds. I got 5 m/s

b. Determine the sprinters velocity after 2 seconds have elapsed. I couldn't decide on 5 m/s^2 or 10 m/s^2 because i used Vf=Vo+at and V=d/t and it gave me those two different answers.

c. Determine the total time needed to run the full 100 meters. I got 6.32s which is unrealistic.





Please help me out I'm a little rusty just starting physics two and would love for you guys to solve and compare answers. Thank you!

cacc.gif


You have the time (t= 2 s), and the distance (y= 10 m), so you can easy calculate the acceleration.
 

Related to Kinematics Problem: Sprinter Acceleration and Velocity

1. What is kinematics?

Kinematics is the branch of physics that deals with the study of motion, without considering the forces that cause the motion.

2. What are the basic equations used in kinematics problems?

The basic equations used in kinematics are the equations of motion, which include: displacement = initial velocity x time + 1/2 x acceleration x time^2, final velocity = initial velocity + acceleration x time, and average velocity = (initial velocity + final velocity)/2.

3. How do I approach a kinematics problem?

To solve a kinematics problem, you should first identify the known and unknown variables, then choose the appropriate equation(s) to use, and finally substitute the values and solve for the unknown variable.

4. What are the different types of motion in kinematics?

The different types of motion in kinematics include linear motion (motion in a straight line), rotational motion (motion around an axis), and projectile motion (motion of an object in a curved path).

5. How can I check my answer for a kinematics problem?

You can check your answer for a kinematics problem by using the equations of motion to calculate the other variables and seeing if they match the given values. You can also use the laws of conservation of energy and momentum to check your answer.

Similar threads

  • Introductory Physics Homework Help
Replies
4
Views
842
  • Introductory Physics Homework Help
Replies
18
Views
2K
  • Introductory Physics Homework Help
Replies
4
Views
2K
  • Introductory Physics Homework Help
Replies
13
Views
857
  • Introductory Physics Homework Help
Replies
17
Views
1K
  • Introductory Physics Homework Help
Replies
1
Views
1K
  • Introductory Physics Homework Help
Replies
5
Views
1K
  • Introductory Physics Homework Help
Replies
7
Views
1K
  • Introductory Physics Homework Help
Replies
2
Views
3K
  • Introductory Physics Homework Help
Replies
5
Views
1K
Back
Top