Two planes are about to drop an empty fuel tank. At the moment of release each plane has the same speed of 195 m/s, and each tank is at the same height of around 1.10 km above the ground. Although the speeds are the same, the velocities are different at the instant of release, because one plane is flying at an angle of 15° above the horizontal (Plane A) and the other is flying at an angle of 15° below the horizontal (Plane B). 1. Find the:

a. magnitude.
b. direction of the velocity with which the fuel tank hits the ground if it is from plane A.

2. Find the:

a. magnitude
b. direction of the velocity with which the fuel tank hits the ground if it is from plane B.

In each part, give the direction as a positive angle with respect to the horizontal.

Scientists use laser range-finding to measure the distance to the moon with great accuracy. a brief laser pulse is fired at the moon, then the time interval is measured until the "echo" is seen by a telescope. a laser beam spreads out as it travels because it diffracts through a circular exit as it leaves the laser. in order for the reflected light to be bright enough to detect, the laser spot on the moon must be no more than 1.0 km in diameter. staying within this diameter is accomplished by using a special large-diameter laser. part a if λ = 540nm , what is the minimum diameter of the circular opening from which the laser beam emerges? the earth-moon distance is 384,000 km. express your answer to two significant figures and include the appropriate units.

Sodium chloride, nacl, is formed when a sodium atom transfers its electron to a chlorine atom. the difference in charge between the two atoms creates a(n) attraction that bonds them together.

Which are true about beta reactions? there will be more than one answer. a. it has no change b. it doesn't change the mass of the number c. it has a mass of 0.0005 atoms d. it causes transmutation.