Metals are not brittle so it can’t be the first one or the third one, both metalloids and metals are shiny so it can’t be the second one. Therefore, it would be the last one because both metalloids and metals are shiny and both are solids at room temperature because it is not a high enough melting point.
ANSWER: Both are shiny and are solid at room temperature.
It is not possible because if they stop so quickly the surfboard with the motion forward continuing the motion of the van, not backwards
This isn’t the greatest, but I hope it helps
Answer: the answer should be 6,720 decameters.
Answer:
The maximum height of the ball is 20 m. The ball needs 2 s to reach that height.
Explanation:
The equation that describes the height and velocity of the ball are the following:
y = y0 + v0 · t + 1/2 · g · t²
v = v0 + g · t
Where:
y = height of the ball at time t
y0 = initial height
v0 = initial velocity
t = time
g = acceleration
v = velocity at time t
When the ball is at its maximum height, its velocity is 0, then, using the equation of the velocity, we can calculate the time at which the ball is at its max-height.
v = v0 + g · t
0 = 20 m/s - 9.8 m/s² · t
-20 m/s / -9.8 m/s² = t
t = 2.0 s
Then, the ball reaches its maximum height in 2 s.
Now, we can calculate the max-height obtaining the position at time t = 2.0 s:
y = y0 + v0 · t + 1/2 · g · t²
y = 0 m + 20 m/s · 2 s - 1/2 · 9,8 m/s² · (2 s)²
y = 20 m