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1. An ice skater is spinning fast with her arms tight against her body. When she extends her arms, which of the following statements is not true?

• She increases her moment of inertia.
• She decreases her angular velocity.
• Her moment of inertia remains constant.
• Her total angular momentum will remain constant.

 

2. Two objects of masses 1 x 10^-3 kg and 4 x 10^-3 kg have equal momentum. What is the ratio of their kinetic energies?

• 4:1
• 2:1
• 16:1
• 2^1/2 :1

 

3. Which of the following statements about nuclear fission is always correct?

• Very little energy is released in fission processes.
•  Nuclear fission is an energetically favorable process for heavy atoms.
•  Due to its instability, ⁵⁶Fe readily undergoes fission.
•  In fission reactions, a neutron is split into a proton and an electron.

 

 

4. A and B are two objects with masses 100 kg and 75 kg respectively, then ________ .

• both will have the same inertia
• B will have more inertia
• A will have more inertia

• both will have less inertia

 

5. Two objects, A and B, have the same size and shape. Object A is twice as massive as B. The objects are simultaneously dropped from a high window on a tall building. (Neglect the effect air resistance.) The objects will reach the ground at the same time but object A will have a greater ___. Choose all that apply.
   • Speed
   • Acceleration
   • Momentum
   • None of the above quantities will be greater