1. Give an example of a situation in which a force is applied but no work is done.
2. Define mechanical advantage. Write its formula.
3. Why are roads in hilly regions made winding?
4. How does a pulley help to make work easier?
5. What is a force multiplier? Give three examples of force multipliers.
Answers
1.Consider a coolie carrying a load on his head across a levelled road. He exerts an upward force which is equal to the weight of the load. But the displacement of the load is in the horizontal direction. The angle between force Fand displacement s is 90°.
Hence, W = Fs cos 90° = 0
2.The theoretical mechanical advantage of a system is the ratio of the force that performs the useful work to the force applied, assuming there is no friction in the system. In practice, the actual mechanical advantage will be less than the theoretical value by an amount determined by the amount of friction.
The formula of mechanical advantage is given as: Wherein, MA is the mechanical advantage, FB = force of the object and. FA = effort to overcome the force of the object.
3.Hill roads are made to wind around hills because it is easier to climb along a winding road with a gentle slope than to climb a steep, straight road up a hill.
4.A pulley system makes it easier to lift an object than lifting the dead weight by hand. A single pulley essentially changes the direction of the pull or force applied. When a person uses two or more pulleys in a system, then the system also multiplies the force applied besides changing its direction.
5.Force Multipliers are tools that help you Amplify your effort to produce more output. A hammer is a force multiplier. Investing in Force Multipliers means that you'll get more done with the same amount of effort.
Hammers, wheel barrows, spanners and car jacks are examples of force multipliers.
~Maybe it's helpful❤