What is the inverse tangent of 0.9?

An fm radio station broadcasts at 99.5 mhz. calculate the wavelength of the corresponding radio waves.

True or false An object that is not accelerating or decelerating has zero net force acting in it.

A helicopter lifts a 66 kg astronaut 18 m vertically from the ocean by means of a cable. The acceleration of the astronaut is g/15.

Which statement accurately classifies helium? A. it is an atom B. It is a mixture C. It is a molecule D. It is a compound

A projectile proton with a speed of 610 m/s collides elastically with a target proton initially at rest. The two protons then move along perpendicular paths, with the projectile path at 47° from the original direction.

A proton has an initial speed of 3.7*10^5 m/s. a) What potential difference is required to bring the proton to rest? (V) b) What potential difference is required to reduce the initial speed of the proton by a factor of 2?

If a ball is dropped from rest from an elevated position at the same instant that a second ball is launched horizontally (from the same height), then which ball will hit the ground first? Assume the balls behave as projectiles

What are 5 Non-Examples of Density

With the switch closed, how does the voltage across the 20-ω resistor compare to the voltage across the 10-ω resistor?

A 5.90-g lead bullet traveling at 410 m/s is stopped by a large tree. If half the kinetic energy of the bullet is transformed into internal energy and remains with the bullet while the other half is transmitted to the tree, what is the increase in