Answer:
Option B: Group
Explanation:
The elements fluorine, chlorine, and iodine are commonly known as halogens.
They all have 7 valence electrons in their outermost shell and thus they all belong to group 7A in the periodic table.
Correct Answer is: Group
Around 8 hours and 20 minutes
Explanation:
I divided 500 by 60 and got 8.3333333333 and i round it up to 8.20, so it is 8 hours and 20 minutes.
Hello there,
It takes 300 newtons of force and a distance of 20 meters for a moving cart to come to a stop. How much kinetic energy did this cart have?
Answer: 6000
Answer:
Explanation:
A mass of 700 kg will exert a force of
700 x 9.8
= 6860 N.
Amount of compression x = 4 cm
= 4 x 10⁻² m
Force constant K = force of compression / compression
= 6860 / 4 x 10⁻²
= 1715 x 10² Nm⁻¹.
Let us take compression of r at any moment
Restoring force by spring
= k r
Force required to compress = kr
Let it is compressed by small length dr during which force will remain constant.
Work done
dW = Force x displacement
= -kr -dr
= kr dr
Work done to compress by length d
for it r ranges from 0 to -d
Integrating on both sides
W = 
= [ kr²/2]₀^-4
= 1/2 kX16X10⁻⁴
= .5 x 1715 x 10² x 16 x 10⁻⁴
= 137.20 J