A sphere of mass 3 kg strikes at velocity of 5 m/s to another sphere of mass 2 kg, which is at rest. What would be their common velocity, if they move together after collision?

This question was previously asked in
BHEL Engineer Trainee Mechanical 24 Aug 2023 Official Paper
View all BHEL Engineer Trainee Papers >
  1. 6 m/s
  2. 3 m/s
  3. 9 m/s
  4. 12 m/s

Answer (Detailed Solution Below)

Option 2 : 3 m/s
Free
BHEL Engineer Trainee Fluid Mechanics Mock Test
1.4 K Users
20 Questions 20 Marks 15 Mins

Detailed Solution

Download Solution PDF

Concept:

When two bodies collide and move together after the collision, the principle of conservation of momentum is applied.

The equation for conservation of momentum is given by:

\( m_1 v_1 + m_2 v_2 = (m_1 + m_2) v_f \)

Where:

  • \( m_1 = 3 \) kg (mass of first sphere)
  • \( v_1 = 5 \) m/s (velocity of first sphere before collision)
  • \( m_2 = 2 \) kg (mass of second sphere)
  • \( v_2 = 0 \) m/s (velocity of second sphere before collision, since it is at rest)
  • \( v_f \) is the common velocity after collision

Calculation:

Applying the conservation of momentum equation:

\( (3 \times 5) + (2 \times 0) = (3 + 2) v_f \)

\( 15 = 5 v_f \)

\( v_f = \frac{15}{5} = 3 \) m/s

Latest BHEL Engineer Trainee Updates

Last updated on Jul 8, 2025

-> The BHEL Cut Off 2025 has been uploaded on July 8, 2025 at the official website 

-> BHEL Engineer Trainee result has been released on July 8. 

-> BHEL Engineer Trainee answer key 2025 has been released at the official website. 

-> The BHEL Engineer Trainee Admit Card 2025 has been released on the official website.

->The BHEL Engineer Trainee Exam 2025 will be conducted on April 11th, 12th and 13th, 2025

-> BHEL Engineer Trainee 2025 Notification has been released on the official website.

-> A total of 150 Vacancies have been announced for various disciplines of Engineering like Mechanical, Electrical, Civil, etc.

-> Interested and eligible candidates can apply from 1st February 2025 to 28th February 2025.

-> The authorities has also released the BHEL Engineer Trainee Pattern 

-> The BHEL Engineer Trainee Selection Process is divided into two stages namely Written Test and Interview.

-> The selected candidates for the Engineer Trainee post will get a salary range between Rs. 60,000 - Rs. 1,80,000.

More Kinematics and Kinetics Questions

Get Free Access Now
Hot Links: teen patti master apk download teen patti online game teen patti royal