Apiece of copper of mass 100 g is being drilled through with a 1/2" electric drill. the drill operates at 40.0 w and takes 30.0 s to bore through the copper.

if all the energy from the drill heats the copper, find the copper's increase in temperature. ccopper = 387 j/kg⋅°c.

a. 40.6 c°b. 34.7 c°c. 31.0 c°d. 27.3 c°

correct option is c. 31.0°C  

Explanation:

given data

copper of mass = 100 g

electric drill = 1/2"

power = 40.0 W

time = 30 s

C copper = 387 J/kgC

to find out

copper's increase in temperature

solution

we get here energy that is express a s

energy = 40 W × 30 s

energy = 1200 Watt seconds

and heat acquired by drill is here as

heat acquired = 100 × T × 387  

here temperature rise in copper mass as

temperature rise in copper mass = × T × 387

temperature rise in copper mass = 38.7 ×  T Watt second

we know that all the energy from the drill heats the copper

so we can say

38.7 ×  T = 1200

T = 31°C  

so correct option is c. 31.0°C  

from 1609, galileo galilei used the recently invented telescope to observe the sun, moon and planets. he saw the mountains and craters of the moon, and for the first time revealed the planets to be worlds in their own right. galileo also provided strong observational evidence that planets orbited the sun.

his discoveries about the moon, jupiter's moons, venus, and sunspots supported the idea that the sun - not the earth - was the center of the universe, as was commonly believed at the time.galileo turned his gaze toward venus, the brightest celestial object in the sky - other than the sun and the moon.

r = ρ x length / area  

ρ = r x area / length  

ρ is in ohm-meters  

in basic units, it is m³kg/s³a²  

i think this is it.