How Long Does It Take a Sled to Reach 24 m/s on an Incline?

In summary: The angle is necessary to accurately calculate the acceleration of the sled. In summary, the problem involves a sled starting from rest and sliding down an inclined plane with constant acceleration. In three seconds, it has traveled 9m. To determine the time it takes to reach a velocity of 24m/s, we need to calculate the sled's acceleration. This is done using the formula vf = vi + a * t, where vi = 0. However, we cannot use the standard acceleration due to gravity of 9.81 m/s^2 because the angle of the ramp is not given. Thus, we need to use a different method, such as breaking down the motion into horizontal and vertical components, to accurately calculate the acceleration of the
  • #1
Nanu Nana
95
5

Homework Statement


A sled starts from rest and slides down an inclined plane with constant acceleration. In three seconds, it has traveled 9m. How long does it take to reach a velocity of 24m / s?

Homework Equations


d = vi * t + ½ * a * t^2, vi = 0[/B]
vf = vi + a * t, vi = 0

The Attempt at a Solution


d = vi * t + ½ * a * t^2, vi = 0
9 = ½ * a * 3^2
a = 18 ÷ 9 = 2 m/s^2
To determine the time, we need to determine the sled’s acceleration.

vf = vi + a * t, vi = 0
24 = 2 * t
t = 12 seconds.[/B]
I solved this problem with help of someone else . The thing I don't understand is why can't we use 9,81 m/s2 for acceleration . Because the sled is sliding down . Doesn't it has to do with gravity ?
 
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  • #2
You can't use 9.81 because the ramp is not completely vertical. Only a portion of the acceleration due to gravity is accelerating the sled
 
  • #3
But this can be a 2D motion right ? with horizontal and vertical components ?
 
  • #4
yes, it can.
 
  • #5
rpthomps said:
yes, it can.

To explore it using horizontal and vertical components you would need the angle of the plane though
 
  • #6
Oh that's right . The angle is indeed not given . Thank you very much . I know it was a very dumb question .
 
  • #7
Nanu Nana said:
Oh that's right . The angle is indeed not given . Thank you very much . I know it was a very dumb question .

not a dumb question at all
 

Related to How Long Does It Take a Sled to Reach 24 m/s on an Incline?

What is kinematics acceleration?

Kinematics acceleration is the rate of change of an object's velocity over time. It is a vector quantity, meaning it has both magnitude and direction.

How is kinematics acceleration calculated?

Kinematics acceleration can be calculated by dividing the change in velocity by the change in time. It can also be calculated by taking the derivative of an object's velocity with respect to time.

What are the units of kinematics acceleration?

The units of kinematics acceleration are typically meters per second squared (m/s^2) in the SI system. In other systems, it may be expressed as feet per second squared (ft/s^2) or centimeters per second squared (cm/s^2).

What is the difference between average and instantaneous kinematics acceleration?

Average kinematics acceleration is the average rate of change of an object's velocity over a given time interval. Instantaneous kinematics acceleration, on the other hand, is the rate of change of an object's velocity at a specific moment in time.

How does kinematics acceleration relate to other kinematic quantities?

Kinematics acceleration is related to other kinematic quantities such as displacement, velocity, and time through various equations, including the definition of acceleration (a = Δv/Δt) and the equations of motion (v = u + at and s = ut + 1/2at^2).

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