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Distance question!

  • Thread starter allora_97
  • Start date
  • #1
13
0

Homework Statement


A 11 kg block slides down a frictionless slope
which is at angle θ = 24◦. Starting from rest,
the time to slide down is t = 1.85 s.
The acceleration of gravity is 9.8 m/s2 .
(look at image)
What total distance s did the block slide?
Answer in units of m.

Homework Equations


F=ma
F=mg
tan(theta) = Fy/Fx

The Attempt at a Solution


I calculated the acceleration, a = F/m = 22.01116038m/s^2.
I used the time 1.85sec and the acceleration to find the velocity, v = 40.72064671m/s.
I don't know how to proceed from this point?
 

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Answers and Replies

  • #2
110
0

Homework Statement


A 11 kg block slides down a frictionless slope
which is at angle θ = 24◦. Starting from rest,
the time to slide down is t = 1.85 s.
The acceleration of gravity is 9.8 m/s2 .
(look at image)
What total distance s did the block slide?
Answer in units of m.

Homework Equations


F=ma
F=mg
tan(theta) = Fy/Fx

The Attempt at a Solution


I calculated the acceleration, a = F/m = 22.01116038m/s^2.
I used the time 1.85sec and the acceleration to find the velocity, v = 40.72064671m/s.
I don't know how to proceed from this point?
What numbers did you use for F/m?

22 is way too high. It has to be under 9.8
 
  • #3
13
0
I found Fn = mg = 107.8
I used Force = Fn/tan24 = 242.1227642N
then i found a = F/m = 242.1227642N/ 11kg = 22.01116038 m/s^2
 
  • #4
Char. Limit
Gold Member
1,204
14
I think you should have multiplied by tan(theta), not divided by it.
 
  • #5
13
0
thanks
 
  • #6
110
0
I found Fn = mg = 107.8
I used Force = Fn/tan24 = 242.1227642N
then i found a = F/m = 242.1227642N/ 11kg = 22.01116038 m/s^2
There's your mistake.

Multiply the force by sin(theta) then use that force in F/m to get your acceleration.
 

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