| #3651 |
Can potential energy be converted into kinetic energy in machines? |
Yes, as in a falling weight or swinging pendulum |
| #3652 |
What is the principle of conservation of energy in machines? |
Energy input equals useful energy output plus energy lost to friction or other factors |
| #3653 |
What is the relationship between work input, work output, and efficiency? |
Efficiency = (Work output / Work input) × 100% |
| #3654 |
What is work input and work output in a machine? |
Work input: effort × distance; Work output: load × distance moved by load |
| #3655 |
Can energy be lost in machines? |
Yes, due to friction, air resistance, or deformation |
| #3656 |
How is mechanical advantage of a pulley system calculated? |
MA = Load / Effort |
| #3657 |
What is the difference between fixed and movable pulleys? |
Fixed pulley changes direction; movable pulley reduces effort |
| #3658 |
What is a pulley? |
A wheel with a grooved rim used to change the direction of a force or lift loads |
| #3659 |
How is mechanical advantage of an inclined plane calculated? |
MA = Length of slope / Height of plane |
| #3660 |
What is an inclined plane? |
A flat surface inclined at an angle to the horizontal, used to raise or lower loads |
| #3661 |
How is mechanical advantage of a lever defined? |
Ratio of load force to effort force |
| #3662 |
What are the three types of levers? |
First-class, second-class, and third-class levers |
| #3663 |
What is a lever? |
A rigid bar that rotates about a fulcrum to lift or move loads |
| #3664 |
Name the types of simple machines. |
Lever, Inclined Plane, Pulley, Wheel and Axle, Screw, Wedge |
| #3665 |
What is a simple machine? |
A device that changes the magnitude or direction of a force to make work easier |
| #3666 |
How is efficiency of a machine calculated? |
Efficiency = (Useful work output / Total work input) × 100% |
| #3667 |
What is the SI unit of power? |
Watt (W) |
| #3668 |
What is power? |
Rate at which work is done, P = W/t |
| #3669 |
Can mechanical energy be converted from one form to another? |
Yes, between kinetic and potential energy |
| #3670 |
What is the law of conservation of mechanical energy? |
The total mechanical energy (KE + PE) of a body remains constant if only conservative forces act |
| #3671 |
What is potential energy? |
Energy possessed by a body due to its position or configuration, PE = mgh |
| #3672 |
What is kinetic energy? |
Energy possessed by a body due to its motion, KE = ½ mv² |
| #3673 |
When is work said to be negative? |
When the force and displacement are in opposite directions |
| #3674 |
When is work said to be positive? |
When the force and displacement are in the same direction |
| #3675 |
What is the SI unit of work? |
Joule (J) |