Amy and Andy are studying projectile motion. Amy notes that a projectile launched straight up at 98 m/s will take 10 seconds to reach its peak of 490 m, but it doesn’t take half the time to go half the height. In fact, it takes only about 2.9 seconds to go up the first half, and 7.1 seconds to go up the second half. Andy has an idea: If that projectile were launched at an angle (any angle), the ratio of times (t(1st half)/t(2nd half) ) should remain constant. Perform calculations to support or refute this statement, and provide an explanation.

What happens to the velocity of the car when the upward pull of the cable is greater than the downward pull of gravity as the car rises toward the top?

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.

In a given chemical reaction, the energy of the products is greater than the energy of the reactants. which statement is true for this reaction?