1.7 energy and efficiency Flashcards
1
Q
What is the efficiency of a device?
A
The efficiency of a device = useful energy transferred by the device / total energy supplied to the device (x100)
2
Q
What is the highest efficiency energy transfer can have?
A
No energy transfer can be more than 100% efficient
3
Q
Why do machines waste energy?
A
Machines based energy because of the friction between their moving parts, air resistance, electrical resistance and noise
4
Q
How can machines be made more efficient?
A
Machines can be made more efficient by reducing the energy waste (lubrication is used to reduce friction between moving parts)
