Question

question 9 1 pts a freight train rolls along a track with considerable momentum. if it rolls at the same speed but has twice as much mass, its momentum is unchanged. zero. twice. four times as much. question 10 1 pts a same - size iron ball and wooden ball are dropped simultaneously from a tower and reach the ground at the same time. the iron ball has a greater acceleration. speed. momentum. all of the above none of the above

Explanation:

Step1: Recall momentum formula

The formula for momentum is $p = mv$, where $p$ is momentum, $m$ is mass and $v$ is velocity.

Step2: Analyze Question 9

Let the initial mass be $m_1$ and velocity be $v_1$, so initial momentum $p_1=m_1v_1$. New mass $m_2 = 2m_1$ and $v_2=v_1$. Then new momentum $p_2=m_2v_2=(2m_1)v_1 = 2(m_1v_1)=2p_1$.

Step3: Analyze Question 10

Since both balls are in free - fall, they have the same acceleration $g$ (acceleration due to gravity) and reach the ground at the same time, so they have the same final speed $v = gt$. But the iron ball has greater mass $m$. Using $p = mv$, with same $v$ and greater $m$ for iron ball, it has greater momentum.

Answer:

Question 9: C. twice
Question 10: C. momentum