Amass of 0.40 kg is suspended on a spring which then stretches 10 cm. the mass is then removed and a second mass is placed on the spring which stretches the spring and does 20 j of work. how far is the spring stretched as a result of the work done by the second mass?

 x' = 1.01 m

Explanation:

given,

mass suspended on the spring, m = 0.40 Kg

stretches to distance, x = 10 cm  = 0. 1 m

now,

we know

m g = k x

where k is spring constant

0.4 x 9.8 = k x 0.1

  k = 39.2 N/m

now, when second mass is attached to the spring work is equal to 20 J

work done by the spring is equal to

 x'² = 1.0204

 x' = 1.01 m

hence, the spring is stretched to 1.01 m from the second mass.

second mirror gathers light from a faraway object and reflects it to another mirror. - a.

they are non-matter

explanation:

they are non-matter. basically, any type of energy or any abstract concept is an example of something that does not matter. other examples include dreams, magnetism, radio, and hate