What is this poem what has 88 keys but cannot open any door

The peregrine falcon is the fastest of flying birds (and, as a matter of fact, is the fastest living creature). A falcon can fly 2.73 km downward in 35 s. What is the average velocity of a peregrine falcon?

What is the energy of a single photon of ultraviolet light with a wavelength of 30.0 nm? 1 nm=10^-9 m

An experiment is performed to obtain the value of a physical property. If the true (i. e., correct) value of the property is 50 and the measured (i. e., experimental) value is 32, the percent error of the experimental result is:

A cart at the top of a hill is released and rolls down the hill. Which of the following describes the energy of the cartjust as it reaches the bottom of the hill?

A computer technician always touches the metal body of a computer before touching any of its electrical parts. why?

How to find acceleration

Which of the following involves the emission of a particle that has the same mass of an electron with a positive charge. a. alpha decay c. positron emission b. beta decay d. nuclear forces

Which of the following is an example of distance

What outside force slows down a parachute?

A cable applies a vertical force to a crate with a mass of 70.0 kg. It first lifts the crate to a height of 12.0 m above the floor, and then lowers it back to the floor. What is the total work done by the force?