The exercise of simple machine

8th grade

SMP N 2 SEMARANG 08-09

1. In the lever system shown in the above diagram, the mass of load P is more than the mass of load Q. Which of the following position could be the point of equilibrium?

2. The diagram shows a lever that is balanced. What is the reading of the spring balance and the class of the lever?

3. Among the following tools, which belongs to the same class of lever as a fishing rod?

a. Scissors

b. Paper cutter

c. Bottle opener

d. Ice tongs

4. Among the following tools, which is classified under the same class of lever as the tool shown in the diagram ? a. Pliers

b. Broom

c. Wheelbarrow

d. Bottle opener

5. Among the following, which correctly shows the model of the lever system for ice tongs?

6. The diagram shows a bottle opener that is being used to open the lid of a bottle. Among the following, which is correct?

Fulcrum

Effort

Load

AL

M

N

BN

L

M

CM

L

N

DN

M

L7. The diagram shows a student holding a book. Among P,Q,R and S, which is the location of fulcrum?

8. Among the following tools, which uses the class of lever as shown in the behind diagram?

IKnife

IIBadminton racket

IIIWheelbarrow

AI only

BI and II only

CII and III only

DI, II, and III

9. Which of the following tools is classified in the same class of lever as the wheelbarrow?

APliers

BScissors

CPaper cutter

DFishing rod10. Among the following, which needs an effort of 20 N so that the rod becomes balanced?

AI only

BI and II only

CII and III only

DI, II, and III

11. Among the following, which correctly shows the points of P, Q and R for the lever system in the diagram above?

I

P - Fulcrum

IIQ - Load

IIIR - Effort

AI only

BI and II only

CII and III only

DI, II, and III

12. The diagram shows a ice tongs. Which of the position labelled A, B, C and D requires the least effect to hold the ice cube?

Which of the following tools belongs to the same class of lever as the tools listed above?

AScissors

BPaper cutter

CNutcracker

DFishing rod13. Which of the following tools is true about first-class lever?

AThe effort and load act in the different direction

BThe fulcrum is between the effort and load

CA big load requires a small amount of effort to lift it

DThe effort is always farther from the fulcrum

14. Which of the following pairs of class of lever and tool is matched correctly?

Class of lever

Tool

A Second-class

Pliers

B First-class

Fishing rod

C Third-class

Knife

DSecond-class

Scissors15. What is the difference between the first, second and third class lever ?

16. The figure shows a device that uses a lever system.

(a)Label the above figure showing the positions of fulcrum, effort and load.

___________________________________________________________

(b)What is the direction of action for the effort and load?

___________________________________________________________

(c)State two other examples of tools that use the same kind of lever system.

___________________________________________________________

(d) State one advantage of the class of lever shown by a fishing rod.

_________________________________________________________

(e) If the distance of the fish from the effort and the fulcrum are 60 cm and 100 cm respectively, calculate the weight of the fish if an effort of 400 N is required to lift the fish.

17. A device that acts as a lever, what is the distance of the load from the fulcrum and the distance of the effort from the fulcrum ? Count the Mechanical Advantage!

18. How can the worker move the larger rock easily, shown the figure below, how many force needed to move the rock, if the weight of rock 2000 N?19. A is 400 N, B 600 N, play with the lever as seen on the figure, C is 200 N want to joint to play, how C sit to make the lever balance?

x

D

x

C

x

A

B

x

EMBED PBrush

EMBED PBrush

EMBED PBrush

EMBED PBrush

EMBED PBrush

EMBED PBrush

Ice cube

Crowbar

Pliers

EMBED PBrush

30 cm

50 cm

2 m

40 cm

A

B

C