Answer:
a) 
b) imagen adjunta
Explanation:
a) Primero debemos hacer la conversión de 81 km/h a m/s, esto es 22.5 m/s.
Ahora, usando la ecuacion cinemática, en un movimiento acelerado tenemos:

Queremos encontrar la posición hasta detenerse, osea vf = 0.



b) Para este caso el gráfico se encuentra adjunto.
Espero que te sirva de ayuda!
Answer: 52.
Explanation: Critical Thinking When a ball is thrown vertically up, it keeps going up until it hits a certain position, and then falls down. At the maximum point, the velocity is instantaneously zero.
I may or may not be a nerd lol.
Hope This Helps!!! : )
The answer to this question is going to be False
These energy exchanges are not changes in kinetic energy. They are changes in bonding energy between the molecules. If heat is coming into a substance during a phase change, then this energy is used to break the bonds between the molecules of the substance. The example we will use here is ice melting into water.