Answer:
Speed is acceleration or a high rate of motion
You've been hearing "acceleration of gravity is 9.8 m/s²" for so long,
and you've heard it so many times, that you can recite it in your sleep.
But you're not clear on what it means or what to do with it. If you were,
then you could answer this question in your sleep too.
It means:
When gravity is the only force on an object, it adds 9.8 m/s to
the object's downward speed every second.
If the object happens to be going up, then gravity makes it go up
9.8 m/s slower every second, until it stops going up.
When the object in the picture leaves Mary's hand, it's going up at 29.4 m/s.
After that, gravity is the only force acting on it, SO . . .
-- After 1 sec, it's rising 9.8 m/s slower. That's (29.4 - 9.8) = 19.6 m/s.
In the first second of rising, its speed shrinks from 29.4 m/s to 19.6 m/s.
-- After 2 sec, it's rising ANOTHER 9.8 m/s slower.
In the 2nd second of rising, its speed shrinks from 19.6 m/s to 9.8 m/s.
-- After 3 sec, it's rising ANOTHER 9.8 m/s slower. (9.8 - 9.8) = 0 m/s.
In the 3rd second of rising, its speed shrinks from 9.8 m/s to zero.
After 3 seconds, it has completely run out of upward gas.
Its upward speed has dwindled completely to zero, and
it starts falling.
Answer:
1.78 s
Explanation:
Initial speed of the ball = u = 7.95 m/s and is vertically downwards.
Acceleration due to gravity = g = 9.8 m/s/s , vertically downwards.
Height of the building h = 29.8 m (traversed downwards by the steel ball).
h = u t + 1/2 g t²
29.8 = 7.95 t + 0.5 (9.8) t²
⇒ 4.9 t² +7.95 t - 29.8 = 0
Using the quadratic formula , solve for t.
t= 
t = 
= 1.78 s, -3.4 s
Since time does not have a negative value, time taken by the stone to reach the ground = t = 1.78 s
Answer:
acceleration is the rate of change of velocity
therefore in the above statement, the velocity increases twice per second.
when acceleration is negative, then it is accelerated motion.
ie. the car accelerates twice per second
A because unit means one, i’m almost sure of that
