Answer:
A. Speed is a scalar quantity and velocity is a vector quantity.
Explanation:
A scalar quantity is one that consists of only a numerical value.
Speed is a scalar quantity because only the instantaneous value is indicated, for example the speedometer of a car that tells you your speed at the moment but not where you are going or in what direction are you going.
On the other hand, velocity is a vector quantity. Because it is composed of a <u>magnitude and a direction</u>, for example 10m/s to the south is a velocity, and 10m/s is a speed.
Answer:
2.1 s
Explanation:
The motion of the ball is a projectile motion. We know that the horizontal range of the ball is

And that the initial speed of the ball is

at an angle of

So, the horizontal speed of the ball (which is constant during the entire motion) is

And since the horizontal range is 50 m, the time taken for the ball to cover this distance was

which is the time the ball spent in air.
<em>the energy that is released in the chemical reactions is the exothermic energy ( stored ) in the bonds of reactants... :)</em>
Answer:
false
A hypothesis states a presumed relationship between two variables in a way that can be tested with empirical data. ... The cause is called the independent variable; and the effect is called the dependent variable.