Short-Answer Questions
1. When is work done by a force?
2. Name two things which store chemical
energy
3. Name three forms of energy
4. Define a machine
5. Name four categories of machines.
6. What is a lever? What is its fulcrum?
7. What is load and effort in the context of
a machine?
8. What is the basis on which levers are divided
into three classes?
9. Define the mechanical advantage of a machine
10. What is a force multiplier?
Long-Answer Questions
1. What do you understand by work? Explain
with an example
2. Name four functions which machines can
perform Explain each function with one
example
3. Describe the different parts of a lever
Describe the different classes of levers with
examples
4. Explain the relation between an inclined
plane and a screw. Describe the working of
(a) a jack used to lift a car and (b) a vice
5. Explain clearly what is meant by a wheel
and axle, with two examples. Is it essential
for the wheel section to be circular? Give one
example
6. what is the wedge? how is it similar to an inclined plane ? how does it function as a machine ? maintained two application of a wedge
Answers
Short answer
Ans.1 Work is done whenever a force moves something over a distance. You can calculate the energy transferred, or work done, by multiplying the force by the distance moved in the direction of the force.
Ans 2. The examples of stored chemical energy are biomass, batteries, natural gas, petroleum, and coal. Mostly, when the chemical energy is released from a substance, it is transformed into a new substance complete.
Ans3. Electrical Energy.
- Light Energy.
- Mechanical Energy
Ans4. a piece of equipment with moving parts that is designed to do a particular job. A machine usually needs electricity, gas, steam, etc. in order to work
Ans5. I dont know the answer thanks
Ans 6. A lever is a simple machine made of a rigid beam and a fulcrum. The effort (input force) and load (output force) are applied to either end of the beam. The fulcrum is the point on which the beam pivots. When an effort is applied to one end of the lever, a load is applied at the other end of the lever.
Ans 7. The object being moved by the lever is often called the load, or output force, while the force applied to the lever is called the effort, or input force.
Ans 8.The levers can be classified into three types on the basis of applied force, load and pivot.
Ans 9. Mechanical advantage is a measure of the force amplification achieved by using a tool, mechanical device or machine system. The device trades off input forces against movement to obtain a desired amplification in the output force.
Ans 10. Force Multipliers are tools that help you Amplify your effort to produce more output.
Long answer
Ans1. Work is said to be done when a constant force is applied to an object which causes the object to move in the same direction as the force is applied. The energy that we get from the sun is called solar energy. It is in the form of heat and light. Fossil fuels are an excellent source of energy for the mankind.
Ans 2. I dont know the answer thanks
Ans 3. class 1 lever has the fulcrum between the input force and load. Examples include pliers, scissors, a crow bar, a claw hammer, a see-saw and a weighing balance. ... class 3 lever is a lever that has the input force in between the fulcrum and the load. example include tweezers, swinging a baseball bat etc.
Ans 4. An inclined plane makes work easier by breaking an upward or downward movement into smaller increments. ... A screw is like an inclined plane wrapped around a cylinder. A screw turns a small rotational force into a larger forward driving force.
a part) A jack is a mechanical lifting device used to apply great forces or lift heavy loads. A mechanical jack employs a screw thread for lifting heavy equipment. A hydraulic jack uses hydraulic power. The most common form is a car jack, floor jack or garage jack, which lifts vehicles so that maintenance can be performed.
Ans5. Sorry dont know
Ans 6. A wedge looks like two inclined planes stuck together. The edge of a wedge is often called the blade. The big difference between a wedge and an inclined plane is that, while the inclined plane stays still, a wedge moves to do its work. To chop down a tree, someone has to swing the axe.Force is applied to the thick end of the wedge, and the sloping sides of the wedge apply force to the object, cutting it or splitting it apart. ... This gives the wedge a mechanical advantage greater than 1.