Answer:
NO
Explanation:
No, a machine cannot be 100% efficient. This is due to the movement of the moving parts siding against each other and causing friction. This friction is the one that creates heat and causes wear and tear between moving ports f the machine hence making the machine to decrease in efficiency with time
Kinetic energy is greatest at the lowest point of a roller coaster and least at the highest point
Answer:
Physical quantity is a physical property of an object or material that can be expressed by magnitude and unit.
The derived physical quantities are the type of physical quantities which can be expressed or defined by other physical quantities, called the base quantities. Example: Area, Volume, Velocity
Area- SI Unit: m², U.S. Customary unit: acre
Volume- SI Unit: m³, U.S. Customary unit: cubic inch
Velocity- SI Unit: m/s, U.S. Customary unit: ft/s
Get a pull chord light switch installed in her bathroom by a qualified electrician asap. Meanwhile, keep hands as dry as possible, and try not to go near that switch until it's either been properly earthed, or whatever the problem actually is, and get qualified advice on what the problem is. Don't have wet feet either, and don't stand in puddles of water whilst operating - i she has to - the switch. 250V AC mains can be lethal, and at least painful.
