Linear Impulse-Momentum Principle - Example Problem 9.3-7

 

Find the velocity in m/s of a 12-kg mass, initially resting against a support, after force F acts on the mass for 3 seconds. The time profile of the force is shown in the figure. The angle of the surface is θ = 35 degrees and the coefficient of kinetic friction is 0.4 between the mass and incline.

 

 

Given:

• m = 12 kg
• v₁ = 0
• θ = 35^o
• t = 3 s
• μ_k = 0.4
• state 1 = at rest before F is applied
• state 2 = after F has been applied for 3 seconds

 

Find:

• v₂

 

Video solution:

 

The following video walks you through the solution to this problem. It is suggested that you try solving the problem first and then, if you have difficulties with the solution, watch the video for help.

 

 

Interactive solution:

 

What is F(t)?

 

F(t) = (500/3)t
F(t) = (500)t
F(t) = (3/500)t