What are the differences between concave and convex lenses and mirrors?

A car cruises with constant velocity on a (low traffic) freeway at 70 mph (about 31 m/s). Wind resistance opposes the car's motion with a force of 5000 N.

At one instant in time an LR circuit has a current flowing through it of 44mA. At a time 3.3 us later the current is 22mA. The resistor is 1.0 megaohm. what is the inductance of the inductor? a) 1.1 H b) 2.5 H c) 3.1 H d) 4.8 H

Consider a 24.0 V storage battery that can transfer, over the course of its useful lifetime, a total charge equivalent to 340000 C.

A supply bag is dropped from a rescue plane. After the bag falls for 3.2 seconds, what is the velocity of the bag? How far has the bag fallen? I know the answer to the first one is - 19.6 but im struggling to figure out the second

Potential energy of a 1200 kg boulder on a cliff 45 m above the ground

Power=170 watts time=20 seconds

What is the charge of alpha, beta and gamma rays?

A pair of scissors is a complex machine. what simple machines make up a pair of scissors?

Methane gas absorbs red light, and methane clouds reflect blue light, giving Uranus and Neptune their distinctive blue colors. Why do Uranus and Neptune have methane clouds, but Jupiter and Saturn do not

A car traveled 1025 kilometers from El Paso to Dallas in 13.5 hours. What was it's average velocity?