On a summer afternoon, the sand on the beach can get very hot. when you step on the sand in bare feet, you can burn yourself.
which of the following sentences best describes how this happens?
heat from the sun is transferred to the sand without direct contact. this heat is then transferred to your feet without direct contact.
heat from the sun is transferred to the sand without direct contact. this heat is then transferred to your feet by direct contact.
heat from the sun is transferred to the sand by direct contact. this heat is then transferred to your feet by direct contact.
heat from the sun is transferred to the sand by direct contact. this heat is then transferred to your feet without direct contact.

explanation: in any substance/object, the particles inside it (atoms/molecules) constantly move in random directions and with random speeds (this motion is called brownian motion). as a result, the particles have some kinetic energy (which is proportional to the temperature of the substance).

explanation:

have a great day!

answer: the exterior temperature of commercial jet planes as they leave the stratosphere and return to the ground increases steadily.

explanation:

the lower most layer of atmosphere is troposphere which extends from 0 to 12 km above the surface of the earth. the temperature initially decreases as distance is increased from the earth's surface. commercial jets fly in lower part of the stratosphere. the stratosphere extends upto 50 km. the temperature in stratosphere starts rising again due to presence of ozone which traps the uv rays.

thus, when the planes leave the stratosphere and return to the ground, the exterior temperature increases steadily.