7.A hiker shouts toward a vertical cliff that is 685 m away. The echo is heard 4.0 s later. (a) What is the sound wave’s speed (v)? (b) The wavelength (λ) of the sound is 0.75 m. What is the wave’s frequency (f)? (c) What is the wave’s period (T)?

The harmonic motion of a particle is given by f(t) = 2 cos(3t) + 3 sin(2t), 0 ? t ? 8. (a) when is the position function decreasing? (round you

Alivestock company reports that the mean weight of a group of young steers is 1100 pounds with a standard deviation of 93 pounds. based on the model n(1100,93) for the weights of steers, what percent of steers weigh a) over 1050 pounds? b) under 1300 pounds? c) between 1150 and 1250 pounds?

A1200 kg car traveling north at 10 m/s is rear-ended by a 2000 kg truck traveling at 30 m/s. what is the total momentum before and after the collision?