This topic contains a solution. Click here to go to the answer

Author Question: A karate master strikes a board with an initial velocity of 12.0 m/s, decreasing to 3.0 m/s as his ... (Read 121 times)

humphriesbr@me.com

  • Hero Member
  • *****
  • Posts: 550
A karate master strikes a board with an initial velocity of 12.0 m/s, decreasing to 3.0 m/s as his hand passes through the board. If the time of contact with the board is 0.002 s, and the mass of the coordinated hand and arm is 1.0 kg, what is the force exerted on the board?
 a. 7.5E+3 N
  b. 1.8E2 N
  c. 3.0E2 N
  d. 4.5E+3 N
  e. 6.0E+3 N

Question 2

A boxcar of mass 125 tons at rest becomes uncoupled on a 2.0 grade. If the track is considered to be frictionless, what speed does the boxcar have after 9.0 seconds?
 a. 4.0 m/s
  b. 0.038 m/s
  c. 31 m/s
  d. 3.1 m/s
  e. 0.31 m/s



Related Topics

Need homework help now?

Ask unlimited questions for free

Ask a Question
Marked as best answer by a Subject Expert

af

  • Sr. Member
  • ****
  • Posts: 356
Answer to Question 1

d

Answer to Question 2

d





 

Did you know?

Ether was used widely for surgeries but became less popular because of its flammability and its tendency to cause vomiting. In England, it was quickly replaced by chloroform, but this agent caused many deaths and lost popularity.

Did you know?

In most climates, 8 to 10 glasses of water per day is recommended for adults. The best indicator for adequate fluid intake is frequent, clear urination.

Did you know?

Your skin wrinkles if you stay in the bathtub a long time because the outermost layer of skin (which consists of dead keratin) swells when it absorbs water. It is tightly attached to the skin below it, so it compensates for the increased area by wrinkling. This happens to the hands and feet because they have the thickest layer of dead keratin cells.

Did you know?

In ancient Rome, many of the richer people in the population had lead-induced gout. The reason for this is unclear. Lead poisoning has also been linked to madness.

Did you know?

In the United States, congenital cytomegalovirus causes one child to become disabled almost every hour. CMV is the leading preventable viral cause of development disability in newborns. These disabilities include hearing or vision loss, and cerebral palsy.

For a complete list of videos, visit our video library