Answer:
approximately 30 degrees
Explanation:
If it takes the cannonball 2 seconds to reach the maximum height, we can use the analysis of the vertical component of the velocity and the fact that the acceleration of gravity is the one acting opposite to this initial vertical component
of the velocity. We know as well that at the top of the trajectory, the vertical component of the velocity is zero, and then the movement starts going down in it trajectory. So, the final velocity for the first part of the ascending movement is zero, giving us the following equation for the velocity under an accelerated movement (with acceleration of gravity "g" acting):

By knowing the vertical component of the initial velocity (19.6 m/s), and the actual magnitude of the total initial velocity (40 m/s), we can calculate what angle was the initial velocity vector forming above the horizontal. We use for such the fact that the sine of the angle relates the opposite side of a right angle triangle with the hypotenuse, and solve for the angle using the arcsin function:

which tells us that the closer answer shown is 
From T = 2π√(l/g).
Since the lengths are the same, so that is a constant.
T α 1/√g
So the period T is inversely proportional to the square root of gravity g.
So the one with a bigger gravity g would have a shorter period
and
the one with smaller gravity g would have a longer period.
Therefore the period on the Moon with gravity of 1.63 m/s² would be longer period than that on the Earth with gravity of 9.81 m/s²
It is incorrect, because the identity of the original product has changed. Ca3(OH)2 does not exist! It is no longer calcium hydroxide. To balance an equation, you must manipulate the coefficients, a.k.a. the big numbers that go before reactants or products. Subscripts, the little numbers inside the reactants or products, cannot be changed without completely changing the substance.
Answer:
<h2>If the forefinger points in the direction of the magnetic field and the middle finger in the direction of the current, then, the thumb points in the direction of the force exerted on the conductor.So, if the current is reversed in the conductor placed in a magnetic field the direction of force is also reversed..</h2>
Answer:
Distance per unit time
Explanation:
Speed is the rate at which someone or something is able to move or operate.