« previous next »

Author Question: A machine gun is attached to a railroad flatcar that rolls with negligible friction. If the railroad ... (Read 125 times)

jon_i

  • Hero Member
  • *****
  • Posts: 549
on: Jul 28, 2018
A machine gun is attached to a railroad flatcar that rolls with negligible friction. If the railroad car has a mass of 6.25  104 kg, how many bullets of mass 25 g would have to be fired at 250 m/s off the back to give the railroad car a forward velocity of 0.3 m/s?
 a. 400
  c. 3000
  b. 2000
  d. 5000

Question 2

A proton (+1.6  10-19 C) moves 10 cm on a path in the direction opposite to a uniform electric field of strength 3.0 N/C. How much work is done on the proton by the electrical field?
 a. 4.8  10-20 J
  c. zero
  b. 1.6  10-20 J
  d. -4.8  10-20 J


joshbk44

  • Sr. Member
  • ****
  • Posts: 340
Reply #1 on: Jul 28, 2018
Answer to Question 1

C

Answer to Question 2

D


Related Topics

Need homework help now?

Ask unlimited questions for free

Ask a Question
« previous next »
 

Did you know?

Stevens-Johnson syndrome and Toxic Epidermal Necrolysis syndrome are life-threatening reactions that can result in death. Complications include permanent blindness, dry-eye syndrome, lung damage, photophobia, asthma, chronic obstructive pulmonary disease, permanent loss of nail beds, scarring of mucous membranes, arthritis, and chronic fatigue syndrome. Many patients' pores scar shut, causing them to retain heat.

Did you know?

There are over 65,000 known species of protozoa. About 10,000 species are parasitic.

Did you know?

The Romans did not use numerals to indicate fractions but instead used words to indicate parts of a whole.

Did you know?

The most destructive flu epidemic of all times in recorded history occurred in 1918, with approximately 20 million deaths worldwide.

Did you know?

Multiple experimental evidences have confirmed that at the molecular level, cancer is caused by lesions in cellular DNA.

Schematic hemodialysis machine Schematic hemodialysis machine
Apply friction to tendons at the elbow with thumb or fingers. Add stripping effleurage along length ... Apply friction to tendons at the elbow with thumb or fingers. Add stripping effleurage along length ...
Massage extensor muscles and apply transverse friction over tendons. Knead and press into forearm ... Massage extensor muscles and apply transverse friction over tendons. Knead and press into forearm ...
ECG machine ECG machine
12 question help need please some questions see photos attached 12 question help need please some questions see photos attached
Grand Funk Railroad - Bad Time Grand Funk Railroad - Bad Time
Video: Chemical Messengers Animation

For a complete list of videos, visit our video library