Aball is thrown straight up, reaches a maximum height, then falls to its initial height. which of the following statements about the direction of the velocity and acceleration of the ball as it is going up is correct?
a) its velocity pounts downward and its acceleration points upward.
b) both velocity and its acceleration point upward
c) its velocity points upward and its acceleration points downward
d) both its velocity and its acceleration points downward

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.

Newtons view of arrangement of the universe. don't copy from anywhere.

An alarm clock has a current of 4.5 amps and a resistance of 3.2 ohms. what is the voltage in the circuit? a.1.4 volts b.0.71 volts c.14 volts d.46 volts