# Type Of Simple Machines Study Questions Class-6th Goyal Brothers Physics Solutions Chapter-4 Unit-2

Type Of Simple Machines Study Questions Class-6th Goyal Brothers Physics Solutions Chapter-4 Unit-2. We Provide Step by Step Answers of Study Questions of Chapter-4 ,Energy, Unit-2 (Type Of Simple Machines Study Question). Visit official Website  CISCE  for detail information about ICSE Board Class-6.

## Type Of Simple Machines Class-6th Study Question Goyal Brothers Physics Solutions Chapter-4 Unit-2 Part-2

 Board ICSE Class 6th Subject Physics Book Name Goyal Brothers Chapter-4 Energy Unit-2 Part-2 Type Of Simple Machines Study Question Topic Solution of exercise questions Session 2023-24

### STUDY QUESTIONS

Type Of Simple Machines Class-6th Study Question Goyal Brothers Physics Solutions Chapter-4 Unit-2 Part-2

#### Question: 1.(a) Define lever.

Answer: 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.

#### Question: 2. Give two examples each for levers of first, second and third order.

Answer: First class lever: This is a type of lever which has the fulcrum in between the weight and the force applied. Its order is represented as force-fulcrum-weight. Example: using scissors represents the use of two first-class levers, pulling a nail out of a wooden plank also represents a first-class lever.

Second class lever: In this, the fulcrum is at one end and the force applied is on the other end. The weight is situated in the middle of these two. The order of this would be fulcrum-weight-force. Example: wheelbarrow, staplers

Third class ever: These are the levers in which the fulcrum is at one end and the force is applied in the middle and the weight is on the other end. The order is represented as a weight-force-fulcrum. Example: fishing rod, a broom

#### Question: 3. Classify the following as levers of first, second and third order.

##### (a) Forceps

Answer: Forceps are examples of levers of third-order because the effort is situated between the load and the fulcrum.

##### (b) Lock and key

Answer: Lock and keys are examples of levers of the first order because the fulcrum is between the load and the effort.

##### (c) Pliers

Answer: Pliers are examples of levers of the first order because the fulcrum is between the load and the effort.

##### (d) A fishing rod

Answer: A fishing rod are examples of levers of third-order because the effort is situated between the load and the fulcrum.

##### (e) A nut cracker

Answer: A nutcracker is an example of a lever of second order because the load is situated between the effort and the fulcrum.

##### (f) See-saw

Answer: See-saws are examples of levers of the first order because the fulcrum is between the load and the effort.

#### Question: 4. Why is the mechanical advantage of a lever of second order more than 1 ?

Answer: The effort arm is always longer than the load arm. In Class II levers, the fulcrum and the effort are at the two ends of the lever and the Load is somewhere in between the effort and the fulcrum.

MA of a lever =Effort arm/Load arm

Since, the effort arm is always longer than the load arm .

From the equation above, it is clear that MA of the Class II levers is always greater than 1.

#### Question: 5. Define the term pulley. What for single fixed pulley is commonly used ?

Answer: A pulley is a metallic disc with a grooved rim and a string is passed around the groove at the rim. A pulley that has its axis of rotation fixed in position is called a single fixed pulley. It is used to change the direction of effort.

#### Question: 6. Draw a neat diagram of a single movable pulley and state its one use.

A single fixed pulley is used to change the direction of effort.

#### Question: 7. What is a wheel and axle ? Give two example of wheel and axle.

Answer: The wheel and axle is a simple machine having a wheel and an axle. The linear motion of the axle is obtained by rotating the wheel so as to reduce friction. Example, Steering wheel, screwdrivers, water tap, etc.

#### Question: 8.(a) What is an inclined plane ?

Answer: Slides at the park, steep driveways, and shipping truck loading ramps are all examples of inclines. Inclines or inclined planes are diagonal surfaces that objects can sit on, slide up, slide down, roll up, or roll down.

Inclines are useful since they can reduce the amount of force required to move an object vertically. They’re considered one of the six classical simple machines.

#### (b) Give four daily life examples using inclined plane.

Answer: four daily life examples of inclined planes:

• Ramps.
• Stairs.
• Slides.
• Anthills.
• Slanted roofs.
• Escalators.

#### Question: 9. (a) What is a wedge ? Give three practical examples of a wedge.

Answer: A wedge is a simple machine that consists of two inclined planes situated back-to-back. These inclined planes give the wedge its sharp edge which helps in splitting the objects. A knife, chisels, and axes, are an example of a wedge.

#### (b) What for a wedge is employed commonly ?

Answer: A wedge is commonly employed to tear apart solid objects like wood.

#### Question: 10. (a) What is a screw ?

Answer: Screw is a simple machine which appears like an inclined plane wound around a rod with pointed tip. Hence, it appears like a nail with grooves on its circular curved surfaces.

#### (b) Give three uses of a screw.

Answer: Three uses of screw :

1. Used to fasten two pieces of wood or metal.
2. A cork screw is used for pulling out a cork from the bottles of ketchup or cold drink.
3. Screw jack is basically a nut and bolt arrangement used for lifting one side of a car or a truck, in order to change the punctured wheel.

#### Question: 11. Classify the following simple machines :

##### (a) A railway signal

Answer: A railway signal – It is an example of a Lever of first-order because the fulcrum is in between load and effort.

##### (b) A door knob

Answer: A door knob – It is an example of a lever of second order because the load is in between effort and fulcrum.

##### (c) A jack screw

Answer: A jack screw – a big lever.

##### (d) A staircase

Answer: A staircase – It is an example of an inclined plane because any sloping flat surface along which a load can be easily pushed or pulled is called an inclined plane.

Answer: A bread knife – It is an example of a lever of third-order because the effort is in between the load and effort.

##### (f) A wheel barrow

Answer: A wheel barrow – It is an example of a wheel and axile because Wheelbarrows have a wheel at the fulcrum with a smaller, cylindrical axle at the center. The wheelbarrow’s wheel and axle help it move without friction, making it easier to push and pull.

#### Question: 12. The handle of a water pump is 90 cm long from its piston rod. If the pivot handle is at a distance of 15 cm from the piston rod, calculate (a) least effort required at its other end to overcome a resistance of 60 kgf and (b) mechanical advantage of handle.

length of water pump=90cm

Effort arm = handle of water pump – load arm =90-15=75cm

Formula used :

MA=Effort arm/Load arm ⇒ MA= 75/15 =5

(b) To calculate effort:

Thus, effort the required to overcome resistance or load of 60 kgf is,

Formula used: MA = Load arm/Effort arm

Thus, Effort = Load arm/Effort arm =60kgf/5 = 12kgf

Hence the effort required is 12kgf.

#### Question: 13. A uniform plank of a sea-saw is 5 m long supported at its center. A boy weighing 40 kgf sits at a distance of 1 m from the fulcrum. Where must a girl weighing 25 kgf sit, so as to balance the plank ?

Answer: Here, in the above question, we will use the formula

Given that,

effort = 25N

effort arm = x

by this we can write it as,

25 x X = 40 x 1

x = 1.6m

Conclusion: Hence, the distance from the other end to be placed is 1.6m

#### Question: 14. A nut can be opened by a lever of length 0.25 m by applying a force of 80N. What should be the length of lever, if a force of 32N is enough to open the nut ?

Effort=32N.

Formula:

Principle of the lever.

Step 2: Calculate the length of the effort arm

Substitute the values in the above formula.

Effort arm = 80N × 0.25m/32N = 20/32 = 0.625 m.

Hence, the length of the lever is = o.625

#### Question: 15. An effort of 50 kgf is applied at the end of a lever of the second order which supports a load of 750 kgf. Find the mechanical advantage.

Solution:

Given that,

Effort = 50kgf

let effort arm = E

50 x effort arm = 750 x 0.1

effort arm = 75/50`

Conclusion: Hence, the length of the lever=1.5m

#### Question: 16. A crow-bar of length 2.0 m is used as a machine to lift a box of 100 kgf by placing a fulcrum at a distance of 0.1 m from the box. Calculate the effort required.

Given data,

Total length of crowbar =2m,

Step 2:

Effort arm = Total length crowbar – load arm

Effort arm  2-0.1 =1.9m

Step 3:

Formula:

Substitute the values in the above formula,

Step 4:

Effort = 100/19 = 5.26kgf

Hence, the effort required to lift 100 kgf is 5.26 kgf.

— :End of Type Of Simple Machines Class-6th Study Question Goyal Brothers Physics Solutions Chapter-4 Unit-2 Part-2 :–-

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