a) 2.75 s
The vertical position of the ball at time t is given by the equation
where
h = 4 m is the initial height of the ball
u = 12 m/s is the initial velocity of the ball (upward)
g = 9.8 m/s^2 is the acceleration of gravity (downward)
We can find the time t at which the ball reaches the ground by substituting y=0 into the equation:
This is a second-order equation. By solving it for t, we find:
t = -0.30 s
t = 2.75 s
The first solution is negative, so we discard it; the second solution, t = 2.75 s, is the one we are looking for.
b) -15.0 m/s (downward)
The final velocity of the ball can be calculated by using the equation:
where
u = 12 m/s is the initial (upward) velocity
g = 9.8 m/s^2 is the acceleration of gravity (downward)
t is the time
By subsisuting t = 2.75 s, we find the velocity of the ball as it reaches the ground:
And the negative sign means the direction is downward.
Answer:
Rice
Explanation:
Because I can't control eating lots of rice
<span>The cation is positively charged and has a charge twice that of the anion, for example +2.
The anion is negatively charged and in our example where the cation has a +2 charge, it must have a -1 charge.
In order for the charges to equal zero, there must be two anions: -1 x 2 = -2
So the answer is D. AX2</span>
1. The successful launch of communication satellites
2.More people will be interested in studying science
But science would probably be focused on space exploration and there will probably be less scientists in other fields such as chemistry.
A fixed container containing an ideal gas is heated. The pressure of the gas increases because the molecules move faster.
You can speed up the motion of the molecules in a gas by heating it. The pressure will rise and there will be greater impacts on the container's walls.
The container walls are pressed against by the combined force of the collisions. The energy you provide when you heat the gas makes the gas's particles more kinetically energetic and put more pressure on the container.
As the temperature rises, the pressure must as well since pressure is the force the particles per unit of area exert on the container.
Learn more about pressure and temperature relation here:-
brainly.com/question/1969683
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