free fall in a vacuum container.
Rajah menunjukkan sekeping duit syiling dan
sehelai bulu ayam yang sedang jatuh bebas di dalam
bekas vakum.
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi2WLCba77q1qbLVJ23Yyl-QbyCyq9j8sHBN63Zh9-iaVK6Pmyho2Q7cV7-UKGZgf76TJ30WNEGrQMhyhlFKBfgUzcrLxCnX1kvBmAOGpIkC1_5UyPwwOyl5s0Px71joboHs8x3_H9SiH5K/s320/wqqqqqqqqqqqqqqqqqqqqqqqqqq.jpg)
Which physical quantity is constant?
Kuantiti fizik yang manakah tetap?
A Velocity
B Acceleration
C Momentum
D Kinetic energy
Answer
B