« previous next »

Author Question: A machine gun is attached to a railroad flatcar that rolls with negligible friction. If the railroad ... (Read 118 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?

Walt Disney helped combat malaria by making an animated film in 1943 called The Winged Scourge. This short film starred the seven dwarfs and taught children that mosquitos transmit malaria, which is a very bad disease. It advocated the killing of mosquitos to stop the disease.

Did you know?

Most fungi that pathogenically affect humans live in soil. If a person is not healthy, has an open wound, or is immunocompromised, a fungal infection can be very aggressive.

Did you know?

Acetaminophen (Tylenol) in overdose can seriously damage the liver. It should never be taken by people who use alcohol heavily; it can result in severe liver damage and even a condition requiring a liver transplant.

Did you know?

In inpatient settings, adverse drug events account for an estimated one in three of all hospital adverse events. They affect approximately 2 million hospital stays every year, and prolong hospital stays by between one and five days.

Did you know?

Long-term mental and physical effects from substance abuse include: paranoia, psychosis, immune deficiencies, and organ damage.

Apply circular friction and direct pressure to suboccipital muscles one side at a time.Turn head to ... Apply circular friction and direct pressure to suboccipital muscles one side at a time.Turn head to ...
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 ...
Superficial friction with palms along back. Hands are perpendicular to the spine; apply friction ... Superficial friction with palms along back. Hands are perpendicular to the spine; apply friction ...
ECG machine ECG machine
Physics - Illustrate how you understand charging by rubbing or friction Physics - Illustrate how you understand charging by rubbing or friction
I need help fill up the chart attached phtoto long question I need help fill up the chart attached phtoto long question
Video: Fermentation pathways

For a complete list of videos, visit our video library