<h3><u>Answer;</u></h3>
- Heat is produced
- Light is produced
- Bubbles appear
<h3><u>Explanation;</u></h3>
- Chemical reactions involve the chemical interaction of two or more chemical substances, result in a new substance being formed, and are usually irreversible.
- The signs of chemical reactions include gas formation, energy release in the form of light or flame, heat absorption, precipitate formation, and color change.
Answer:
35.28m/s; 63.50m
Explanation:
<u>Given the following data;</u>
Time, t = 3.6 secs
Since it's a free fall, acceleration due to gravity = 9.8m/s²
Initial velocity, u = 0
To find the final velocity, we would use the first equation of motion;
Substituting into the equation, we have;
V = 35.28m/s
Therefore, the final velocity of the penny is 35.28m/s.
To find the height, we would use the second equation of motion;

Substituting the values into the equation;



S = 63.50m
Therefore, the height of the tower is 63.50m.
Answer:
a = 3.125 [m/s^2]
Explanation:
In order to solve this problem, we must use the following equation of kinematics. But first, we have to convert the speed of 90 [km/h] to meters per second.


where:
Vf = final velocity = 25 [m/s]
Vi = initial velocity = 0
a = acceleration [m/s^2]
t = time = 8 [s]
The initial speed is zero as the bus starts to koverse from rest. The positive sign of the equation means that the bus increases its speed.
25 = 0 + a*8
a = 3.125 [m/s^2]