1. A block on a flat, frictionless surface is pulled by a 20.0 N force to the ri

Question

1. A block on a flat, frictionless surface is pulled by a 20.0 N force to the right and a 5.00 N force to the left. Given that the block moves through a displacement of 2.50 m(to the right), find the work done by each force and the total(net) work.

2. A horizontal spring with k=50.0 N/m is compressed by 0.40m. Next, a mass of 0.63kg is placed against the compressed spring, and the spring is released. Provided the mass remains in contact with the spring until the spring goes back to its original position, find the speed attained by the mass.

3. Two motorboats sail across a bay. One takes a straight-line path and the other one takes a zigzag path. Which one requires more energy to move across the bay, assuming all other factors are constant? Justify your answer.

4. A light is turned on in a dorm room. Identify at least 3 energy transfer mechanism involved.

5. Two springs (each with spring constant 80.0N/m) are placed side-by-side and attached to a mass m. If the springs are stretched by 0.28m, determined the potential energy associated with the spring system.

Explanation / Answer

1.

Work done is given by each force is

W1 =F*s =20*2.50 =50J

W2 =F*s =5*2.50= 12.5J

Now the net work done is Wnet =W1-W2 =37.5J

2)

vf =Sqrt(kx2/m)=Sqrt(50*(0.40)2/0.63)=3.563m/s

3)

One who takes a straight-line path have to require more enrgy to move across the bay.

4)We can see that the electric lamp transfers or converts electrical energy into light energy and heat energy

5)

The resultant force is given by 1/K =1/K1+1/K2 =2/80

Then k=80/2 =40N/m

Now the potential energy of the spring is given by w =(1/2)kx2 =0.5*40*(0.28)2 =1.568J

Related Questions

Navigate

• Browse (All)
• Browse 1
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.