V = 60km/h
S=500km
t = ?
v = S/t
t = S/v
t = 500km / 60 km/h
t ≈ 8,33 h
The ball took half of the total time ... 4 seconds ... to reach its highest
point, where it began to fall back down to the point of release.
At its highest point, its velocity changed from upward to downward.
At that instant, its velocity was zero.
The acceleration of gravity is 9.8 m/s². That means that an object that's
acted on only by gravity gains 9.8 m/s of downward speed every second.
-- If the object is falling downward, it moves 9.8 m/s faster every second.
-- If the object is tossed upward, it moves 9.8 m/s slower every second.
The ball took 4 seconds to lose all of its upward speed. So it must have
been thrown upward at (4 x 9.8 m/s) = 39.2 m/s .
(That's about 87.7 mph straight up. Somebody had an amazing pitching arm.)
The answer is D.Puck.
♡♡Hope I helped!!! :)♡♡
Answer:
The mass of the object involved and the value of the gravitational acceleration
Explanation:
- Gravitational potential energy is defined as the energy possessed by an object in a gravitational field due to its position with respect to the ground:

where m is the mass of the object, g is the gravitational acceleration and h is the heigth of the object with respect to the ground.
- Elastic potential energy is defined as the energy possessed by an elastic object and it is given as:

where k is the spring constant of the elastic object, while x is the compression/stretching of the spring with respect to the equilibrium position.
As we can see from the equations, both types of energy depends on the relative position of the object/end of the spring with respect to a certain reference position (h in the first formula, x in the second formula), but gravitational potential energy also depends on m (the mass) and g (the gravitational acceleration) while the elastic energy does not.