Why is no image formed when an object is at the focal point of a converging lens?

Plz dont type in wrong or just say something to get all my ponit if you do thing willl happen > : l in an environment can destroy entire ecosystems. these changes can occur quickly or over time. which environmental change occurs fastest? volcanic eruption regrowth of forest after volcanic eruption pond succession decomposition of a treeover time the trees in african have increased in length. many species have had to adapt to this change in order to survive. which of the following is a structural adaptation that has the african giraffe meet this change? question 11 options: the african giraffe has become a faster at running from its predators. the african giraffe's neck has increased in size over the years. the african giraffe have moved to another part of africa. the african giraffe has not adapted and struggles to survive. eve and sammy are discussing the affects of farming on the environment. eve states that farming does not harm our environment. she believes that it is only beneficial for the ecosystem and species living in it. sammy states that farming can have major impacts on the environment. he believes farming can cause habitat loss. who is correct? question 12 options: eve is correct because farming only leads to positive affects on ecosystems. sammy is correct because farming has major affects on the environment including soil erosion and flooding. eve is correct because farming does not lead to soil erosion and flooding. neither of them are correct. a power plant recently purchased land and will be building a large factory on wetlands in florida. which of these is not an environmental effect of destroying these wetlands? question 13 options: destroying the wetlands will create a loss of habitat for many species. destroying the wetlands will create flooding. destroying the wetlands will create species to relocate to a new area. destroying the wetlands will change the climate in this area.ever since non-native mussels were introduced into the great lakes, they have caused ecological problems. mussels are very efficient filter feeders. they are better at filtering algae from the water than native species are. which of the following would not result from mussel introduction? question 14 options: excessive growth of mussel populations decline in populations of native mussel species water becoming clearer because mussels eat more algae excessive growth of algae that kills other organismswhat would be an immediate effect of the construction of roads and parking lots on the transfer of energy from producers to consumers in an ecosystem? question 15 options: a decrease in the number of producers a decrease in the number of consumers an increase in the number of producers an increase in the number of consumers

An engineer designs a roller coaster so that a car travels horizontally for 162 ft, then climbs 127 ft at an angle of 31.0° above the horizontal. it then moves 127 ft at an angle of 46.0° below the horizontal. if we take the initial horizontal motion of the car to be along the +x-axis, what is the car's displacement? (give the magnitude of your answer, in ft, to at least four significant figures and give the direction of your answer in degrees counterclockwise from the +x-axis.)

Aspring has a natural length of 8 m. if a 12-n force is required to keep it stretched to a length of 10 m, how much work w is required to stretch it from 8 m to 16 m? (round your answer to two decimal places.)