Given that,
The acceleration of gravity is -9.8 m/s²
Initial velocity, u = 39.2 m/s
Time, t = 2 s
To find,
The final velocity of the shot.
Solution,
Let v is the final velocity of sling shot. Using first equation of motion to find it.
v = u +at
Here, a = -g
v = u-gt
v = (39.2)-(9.8)(2)
v = 19.6 m/s
So, its velocity after 2 seconds is 19.6 m/s.
Explanation:
Given that,
Initial speed of the object, u = 1 m/s
Acceleration of the object, 
We need to find the time when the object comes at rest (v=0). Let it is given by :
t = 1 second
So, the object will comes to rest at 1 second. Hence, this is the required solution.
Answer: <u><em>C. Steel</em></u>
Explanation: <em><u>When a sound wave travels through a solid body consisting</u></em>
<em><u /></em>
<em><u>of an elastic material, the velocity of the wave is relatively</u></em>
<em><u /></em>
<em><u>high. For instance, the velocity of a sound wave traveling</u></em>
<em><u /></em>
<em><u>through steel (which is almost perfectly elastic) is about</u></em>
<em><u /></em>
<em><u>5,060 meters per second. On the other hand, the velocity</u></em>
<em><u /></em>
<em><u>of a sound wave traveling through an inelastic solid is</u></em>
<em><u /></em>
<em><u>relatively low. So, for example, the velocity of a sound wave</u></em>
<em><u /></em>
<em><u>traveling through lead (which is inelastic) is approximately</u></em>
<em><u /></em>
<em><u>1,402 meters per second.</u></em>
<em><u /></em>
<u><em /></u>
