Question

Internal forces can change

• A. the linear momentum but not the kinetic energy of the system
• B. the kinetic energy but not the linear momentum of the system
• C. linear momentum as well as kinetic energy of the system
• D. neither the linear momentum nor the kinetic energy of the system

Answer 1

Answer: (B)

Only external force can change the momentum of the system while internal forces can change the momentum of individual particles and hence the kinetic energy of the system.