1) What is friction? a) Friction is the force which stops the object from slipping b) Friction is what gives the object force to move c) Friction allows the object to stay in a position 2) Why are simple machines used?  a) Simple machinines are machines which help people do simple tasks b) Simple  machines do not do anything c) Simple machines reduce the effort of a person 3) What is balanced force?  a) When both the force are not balanced b) When one force remains unchanged c) When both the forces have equal strength and act in opposite direction  4) What are the advantages of friction a) Friction produces heat which damages the moving parts of a machine. b) Friction produces wear and tear on the contacting surfaces. c) energy is wasted in overcoming the friction before an object starts movin d) Friction enables us to walk freely. 5) Definition of unbalanced force a) the force applied in one direction is greater than the force applied in the opposite direction. b) The amount of force applied on both objects and the are equal c) The force is not counted 6) Why is biomass renewable a) It is renewable as it uses renewable energy b) It uses too much of natural things c) Gets its energy comes from the sun and because it can regrow in a short time. 7) How does solar power generate electricity a) It uses water to generate electricity b) It uses carbon dioxide to generate electricity c) It uses the sun's heat to generate electricity  8) Why is learning push and pull important a) Pushing and pulling on an object can change the speed or direction of its motion and can start or stop it b) We should learn it because they help us know the amount of speed needed

Science

打印
嵌入

排行榜

视觉风格

选项

切换模板

恢复自动保存：？