7. A concave mirror forms on a screen an image of twice the linear dimensions of the object Objcct and screen are then moved until the image is three times the size of
the object. If the shift of the screen is 20cm, determine the shifts of the object and
the focal length of the mirror.

i had this question and the answer was 3.15 miles.

martina travels from school to her mom's office. from there, she walks to school. after school, she walks to the library and then to a friends house before finally ending back at home. find martina's total distance traveled.

a) 0 miles  

b) 0.4 miles  

c) 1 mile  

d) 3.15 miles

find the surface area of the sphere to the nearest square unit. use a calculator.

a. 254 in.2

b. 64 in.2

c. 127 in.2

d. 1,018 in.2