Question

3. A 20 Kg box, initially at rest, is pushed for 2 meters with a force of 50 Newtons. If the frictional force is 30 Newtons, what is the kinetic energy of the box at the end of the 2 meters? Note: this is not a machines problem A see-saw (or a lever) for a playground is 10 meters long. The fulcrum, or pivot point, is placed 2 meters from one end and 8 meters from the other end. What is the mechanical advantage of the see-saw? If 800 Newton weight is placed at the short end of the see- saw, what force must be applied to the 8 meter end to keep the weight from falling? 4.
0 0
Add a comment Improve this question Transcribed image text
Answer #1

3) work done by all forces = change in KE

50*2 - 30*2 = KE - 0

KE = 40 J answer

Add a comment
Know the answer?
Add Answer to:
3. A 20 Kg box, initially at rest, is pushed for 2 meters with a force...
Your Answer:

Post as a guest

Your Name:

What's your source?

Earn Coins

Coins can be redeemed for fabulous gifts.

Not the answer you're looking for? Ask your own homework help question. Our experts will answer your question WITHIN MINUTES for Free.
Similar Homework Help Questions
  • A 4.0 kg box is initially at rest on a table. The box is pushed for...

    A 4.0 kg box is initially at rest on a table. The box is pushed for 3.0 m with a horizonta force of 25 N. The frictional force between the box and table is 12 N. speed of the box after the box is pushed 3.0 meters. 2. Determine the Initial Final g s dis

  • Starting from rest, a 3.2-kg box is pushed on a horizontal floor with a force of...

    Starting from rest, a 3.2-kg box is pushed on a horizontal floor with a force of 482.6 N parallel to the floor. The coefficient of kinetic friction between the box and the floor is 0.5. What is the kinetic energy of the box after it has been pushed with the constant force of 5.8 meters?

  • 003 10.0 points A fulcrum is 1. measured in Joules. 2. the place where a lever...

    003 10.0 points A fulcrum is 1. measured in Joules. 2. the place where a lever is supported. 3. measured in Newton-meters. 4. a support for an inclined plane. 004 10.0 points Which of the statements A. If the effort force is less than the resis- tance force, the mechanical advantage is less than 1 B. A third-class lever requires a larger effort force for a given resistance force; C. The mechanical efficiency of a machine is decreased by reducing...

  • please qickly 2) A 20 kg box initially at rest is pushed 5 m along a...

    please qickly 2) A 20 kg box initially at rest is pushed 5 m along a rough, horizontal floor with a constant applied horizontal force of F = 120 N. The coefficient of kinetic friction between box and floor is 0.1, find; a) (12 p) Calculate the work done by the applied force, the gravitational force, the normal force, the friction force (Wr.W, W.,WR) b) (4 p) Find the change in kinetic energy of the box c) (4 p) Find...

  • 1. A 200 kg crate is pushed across a floor by a force F = 250...

    1. A 200 kg crate is pushed across a floor by a force F = 250 newtons at an angle 0 = 53 below horizontal. The floor exerts a 50 newton frictional force on the crate opposing the motion. a. Draw a labeled free body diagram showing the forces acting on the trunk. (+2) b. Below, write Newtons's 2nd Law (F = må) in the horizontal (x) and vertical (v) direction, using the names of the forces from your free...

  • 1. A box whose mass is 4.3 kg. initially at rest, is pushed in a straight...

    1. A box whose mass is 4.3 kg. initially at rest, is pushed in a straight line for 1.4 m by a constant force of 36 N. Use the work, energy theorem and : a) assuming no friction, what is the final speed of the box at the end of 1.4 m b) suppose there is friction with coefficient 0.2- then what is the final speed?

  • QUESTION 1 A crate at rest resting on a floor: Normal force direction will be: along...

    QUESTION 1 A crate at rest resting on a floor: Normal force direction will be: along the angle of the ramp with respect to the horizontal towards the center of earth parallel to the surface of the ramp perpendicular to the surface of the ramp 1 points    QUESTION 2 A box is at rest on a wooden surface. The frictional force direction in this case will be: Opposite to the direction of the applied force perpendicular to the surface...

  • A 10 kg box is pushed from rest by a truck for 2m. Once the truck...

    A 10 kg box is pushed from rest by a truck for 2m. Once the truck stops pushing the box it is traveling 6 m/s.This box slides for 5 seconds before coming to a stop. If the specific heat is 2 joules per degree kg, how much did the temperature of the box change by and what is the average force applied by the truck?

  • A board has a length of 3 meters and it rests horizontally on two supports. Support...

    A board has a length of 3 meters and it rests horizontally on two supports. Support 1 is 0.38 meters from the left end of the board and support 2 is 0.24 meters from the right end of the board. The normal force from support 2 is 17 Newtons. What is the weight of the board in Newtons?

  • 1. A 4-meter plank weighing 8 kg is lying on a dock with 2.71 meters of...

    1. A 4-meter plank weighing 8 kg is lying on a dock with 2.71 meters of its length on the dock, and the rest of its length extending off the dock. If a child weighing 61.2 kg walks out onto the part of the plank extending off the dock, what is the maximum distance in meters that the child can walk on the plank from the edge of the dock before he falls into the water? 2. A man pulls...

ADVERTISEMENT
Free Homework Help App
Download From Google Play
Scan Your Homework
to Get Instant Free Answers
Need Online Homework Help?
Ask a Question
Get Answers For Free
Most questions answered within 3 hours.
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT