Agrandfather clock is "losing" time because its pendulum moves too slowly. assume that the pendulum is a massive bob at the end of a string. a grandfather clock is "losing" time because its pendulum moves too slowly. assume that the pendulum is a massive bob at the end of a string. the motion of this pendulum can be sped up by: a. shortening the string. b. lengthening the string. c. increasing the mass of the bob. d. decreasing the mass of the bob.

Which changes of state do the labels represent? a: b: c:

A100-watt light bulb illuminates a solar cell. the electricity from the solar cell operates a water pump that delivers 1 watt of power. what is the efficiency of the system?

The base of a 50-meter tower is at the origin; the base of a 50-meter tree is at (0, 50, 0). the ground is flat and the z-axis points upward. the following parametric equations describe the motion of six projectiles each launched at time t = 0 in seconds. (i) r (t) = (50 + t2)k (ii) r (t) = 2t2 j + 2t2k (iii) r (t) = 50 i + 50 j + (50 − t2)k (iv) r (t) = 2t j + (50 − t2)k (v) r (t) = (50 − 2t) i + 2t j + (50 − t)k (vi) r (t) = t i + t j + tk (a) which projectile is launched from the top of the tower and goes downward? at time t = , the projectile hits the ground at point (x, y, z) = . (b) which projectile hits the top of the tree?