Answer:
-30m/s
Explanation:
Given:
Initial velocity of object = 200 feet/second
Final velocity of object = 50 feet/second
Time of travel = 5 seconds
To calculate acceleration of the object we will find the rate of change of velocity with respect to time.
So, acceleration "a" is given by:

where vf represents final velocity, vi represents initial velocity and is time of travel.
Plugging in values to evaluate acceleration.



The acceleration of the object is -30m/s
Answer:
4.7 is 10 as much as the number 0.47.
If you multiply 0.47 x 10 it will equal 4.7
Explanation:
Answer: (b)0.000012/k
Explanation:
The linear expansion of the metal rod is given by

where
is the linear expansion
is the initial length of the rod
is the linear expansivity
is the increase in temperature
By re-arranging the equation, we find the linear expansivity:

Answer:

Explanation:
The ball will rise decreasing its speed until it reaches the highest point where its speed will be zero. From this point the tennis ball will begin to fall again, in the free fall the tennis ball will gain speed but now in the opposite direction. When it returns to the same point where it was launched, its speed will be the same as the one that was launched but with the opposite sign.

We can check this using the equation:

where 
ang h is the height, but because the ball returns to the same point where it started, h =0
then


the initial and final velocity will be the same in number, but we know that the ball is going in the opposite direction, so the final velocity must have the opposite sign from the initial velocity
so if
,
