Answer:C
Explanation:
When a constant horizontal force is applied to the box, box started moving in the horizontal direction such that it moves with constant velocity 
Constant velocity implies that net force on the box is zero
i.e. there must be an opposing force which is equal to the applied force and friction force can serve that purpose.
So option c is the correct choice.
Answer:
Option B is correct.
A double insulated drill generally has a plastic case with the electrical connections and motor insulated within the tool
Explanation:
A double insulated drill's design in real life has plastic casing as the insulator & it wouldn't be a drill without its motor now, would it!?
Energy of a wave:
E = nhc/λ
3000 = (n x 6.63 x 10⁻³⁴ x 3 x 10⁸)/(510 x 10⁻⁹)
n = 7.69 x 10 ²¹ photons per second per meter²
2.70 cm² = 2.70/10,000 m²
= 2.7 x 10⁻⁴
Photons per second = 7.69 x 10 ²¹ x 2.7 x 10⁻⁴
= 2.08 x 10¹⁸ photons per second
The glandular epithelial tissues make up the liver.
Wooden spoons don't quickly heat to hot temperatures not nearly as fast as metal does. Metal conducts heat faster than wood — if the head of the spoon is in a hot liquid, the handle will get hot faster if it's made out of a metal.