Una rueda lisa en su periferia tiene un diámetro de 30 cm a una temperatura de 15°C. El diámetro interior de un aro de acero mide 29.930 cm. ¿A qué temperatura se debe calentar el aro para que pueda ajustar
sobre la rueda? (Cacero = 12 x 10-6°C-1)

Here's link to the

tinyurl.com/wtjfavyw

it's a b and

the aurora is formed when charged particles emitted from the sun during a solar flare penetrate the earth's magnetic shield and collide with atoms and molecules in our atmosphere. these collisions result in countless little bursts of light, called photons, which make up the aurora.

auroras are generated by charged solar particles hitting molecules in earth's atmosphere. this usually happens in high latitudes, because our planet’s magnetic field tends to funnel these particles toward the poles. that’s why it can be experienced in northern ohio.