Answer:
b. v = 0, a = 9.8 m/s² down.
Explanation:
Hi there!
The acceleration of gravity is always directed to the ground (down) and, near the surface of the earth, has a constant value of 9.8 m/s². Since the answer "b" is the only option with an acceleration of 9.8 m/s² directed downwards, that would solve the exercise. But why is the velocity zero at the highest point?
Let´s take a look at the height function:
h(t) = h0 + v0 · t + 1/2 g · t²
Where
h0 = initial height
v0 = initial velocity
t = time
g = acceleration due to gravity
Notice that the function is a negative parabola if we consider downward as negative (in that case "g" would be negative). Then, the function has a maximum (the highest point) at the vertex of the parabola. At the maximum point, the slope of the tangent line to the function is zero, because the tangent line is horizontal at a maximum point. The slope of the tangent line to the function is the rate of change of height with respect to time, i.e, the velocity. Then, the velocity is zero at the maximum height.
Another way to see it (without calculus):
When the ball is going up, the velocity vector points up and the velocity is positive. After reaching the maximum height, the velocity vector points down and is negative (the ball starts to fall). At the maximum height, the velocity vector changed its direction from positive to negative, then at that point, the velocity vector has to be zero.
The universe believed to be has no limit in space and the elements, molecules and different kind of gases are found in this area. So the percentage of that is believed that and ordinary atom can be detected is C. 3% i hope you understand my answer.
Answer:
The unit of energy is joule which depends upon the fundamental unit kg, m and sec. So, the unit of energy is a derived unit.
Explanation:
Answer:
562.5J
Explanation:
The following were obtained from the question:
F = 45N
d = 12.5m
w =?
The work done can be achieved by using
w = F x d
w = 45 x 12.5
w = 562.5J
Answer:
<span>5010J</span>
Explanation:
Work is force times distance, or
<span>W=F⋅d</span>.
Substitute in values from the question to get
<span>W=8.35⋅<span>102</span>N⋅6m=50.1⋅<span>102</span>Nm=5010<span>J</span></span>
