The following 2 questions concern the same physical situation: A steel block of

Question

The following 2 questions concern the same physical situation: A steel block of mass 1.5 kg is sitting atop a table with coefficient of static friction ,- 0.35 and coefficient of kinetic friction ,-0.25. Professor Halfpap is pushing the block as shown in the figure. 2. If the block is at rest, how hard can he push on the block before it will start moving? a. 2.0N b. 4.1 N c. 5.7N d. 5.1 N e. 13.9 N 3. Once the book is traveling at 4 m/s, he stops pushing. How much farther does the book move before coming to rest? a. 6.6m b. 3.3 m c. 2.3 m d. 1.5 m e. 1.2 m

Explanation / Answer

2)

Fmax = us*Fn

Fmax = us*mg

Fmax = 0.35 x 1.5 kg x 9.81 m/s^2

Fmax = 5.1 N

Ans:- d) 5.1 N

3)

Now, there is no acceleration accept kinetic friction.

ma = -uk*mg

a = -uk*g

a = -0.25 x 9.81 m/s^2

a = -2.45 m/s^2

v^2 = vo^2 + 2ax

0 = 4^2 - (2 x 2.45)*x

x = 3.3 m

Ans:- b) 3.3 m

Related Questions

Navigate

• Browse (All)
• Browse T
• Subjects

---