A light meter, because illu is a root for light
Answer:
temperature change is 262.06°K
Explanation:
given data
mass = 0.07 kg
velocity = 258 m/s
to find out
what is its temperature change
solution
we know here
heat change Q is is equal to kinetic energy that is
KE = 0.5 × m× v² ...........1
here m is mass and v is velocity
KE = 0.5 × 0.07 × 258²
KE = 2329.74 J
and we know
Q = mC∆t .................2
here m is mass and ∆t is change in temperature and C is 127J/kg-K
so put here all value
2329.74 = 0.07 × 127 × ∆t
∆t = 262.06
so temperature change is 262.06°K
Answer:In first case
Explanation:
When two People pull the spring, let the applied force by each person be 
and spring constant of spring be k
so Total force is 
total extension according to Hooke's law is
When they detach the spring and apply force in opposite direction then force on either side is F so net extension is
so in first case there will be more extension
The sound was repeated because of the phenomenon of echo. The speed of sound in the metal is 800 m/s.
Echo results from the reflection of sound waves. The reason why a sound may be heard twice owes to the phenomenon of reflection which leads to echo.
To determine the speed of sound in the metal;
Length of metal = 1000 m
Time taken between the two sounds = 2.5 s
Using the formula;
V = 2d/t
V = 2(1000)/2.5
V = 800 m/s
Different wavelengths of light are seen as colors
