A small rock is thrown straight up with initial speed V0 from the edge of the roof of a building with height H. The rock travels upward
and then downward to the ground at the base of the building. Let
+y be upward, and neglect air resistance. (a) For the rock’s motion from
the roof to the ground, what is the vertical component Vav-y of its average
velocity? Is this quantity positive or negative? Explain. (b) What
does your expression for Vav-y give in the limit that H is zero? Explain.
(c) Show that your result in part (a) agrees with Eq. (2.10).

Hugh D. Young, Roger A. Freedman - University Physics with Modern Physics (15th Edition) Chap. 3 Ex. 73

Amass attached to a spring is displaced from its equilibrium position by 5cm and released. the system then oscillates in simple harmonic motion with a period of 1s. if that same mass–spring system is displaced from equilibrium by 10cm instead, what will its period be in this case? a mass attached to a spring is displaced from its equilibrium position by and released. the system then oscillates in simple harmonic motion with a period of . if that same mass–spring system is displaced from equilibrium by instead, what will its period be in this case? a) 0.5sb) 2sc) 1sd) 1.4s

The friction of the water on a boat produces an acceleration of -10. m/s2. if the boat is traveling at 30. m/s and the motor is shut off, how long it take the boat to slow down to 5.0 m/s?

On a horizontal frictionless surface, a small block with mass 0.200 kg has a collision with a block of mass 0.400 kg. immediately after the collision, the 0.200 kg block is moving at 12.0 m/s in the direction 30° north of east and the 0.400 kg block is moving at 11.2 m/s in the direction 53.1° south of east. use coordinates where the +x-axis is east and the +y-axis is north.(a) what is the total kinetic energy of the two blocks after the collision (in ) what is the x-component of the total momentum of the two blocks after the collision? (indicate the direction with the sign of your ) what is the y-component of the total momentum of the two blocks after the collision? (indicate the direction with the sign of your answer.)