A child drops a toy car from a window. The toy car strikes the ground in one second. The child then drops a toy airplane from the same window. What is the velocity of the toy plane the instant
before it hits the ground? (As usual, ignore air resistance.)
REAL ANSWERS PLS EMEEGENCY

Arod of some material 0.20 m long elongates 0.20 mm on heating from 21 to 120°c. determine the value of the linear coefficient of thermal expansion [in (degrees c)^-1] for this material.

Assume that two of the electrons at the negative terminal have attached themselves to a nearby neutral atom. there is now a negative ion with a charge -2e at this terminal. what are the electric potential and electric potential energy of the negative ion relative to the electron? the electric potential and the electric potential energy are both twice as much. the electric potential is twice as much and the electric potential energy is the same. the electric potential is the same and the electric potential energy is twice as much. the electric potential and the electric potential energy are both the same. the electric potential is the same and the electric potential energy is increased by the mass ratio of the oxygen ion to the electron. the electric potential is twice as much and the electric potential energy is increased by the mass ratio of the oxygen ion to the electron.

The diagram shows a wave. the quantity shown is the amplitude. this quantity is directly proportional to which of these other quantities? a) energy b) frequency c) period d) wavelength