Abox of mass 1.0 kg compresses a spring of constant k = 1000 n/m. the spring and box are placed on a smooth horizontal surface and the spring is compressed by 15 cm. the box is released and spring relaxes causing the box to move away. the box encounters a rough patch of coefficient of friction μk=0.4 extending 2 meters. how fast is the box moving after it clears that patch?
a. 6.2 m/s
b. 4.7 m/s
c. 2.6 m/s
d. 7.4 m/s

The atoms in a sidewalk on a hot summer day are vibrating the atoms in the sidewalk on a freezing day in winter. a. more rapidly than b. more slowly than c. at the same speed as

Ais a machine that makes work easier when a single force is applied. a simple machine b compound machine c endangered machine d complex machine

Astone is dropped from the upper observation deck of a tower, 250 m above the ground. (assume g = 9.8 m/s2.) (a) find the distance (in meters) of the stone above ground level at time t. h(t) = (b) how long does it take the stone to reach the ground? (round your answer to two decimal places.) s (c) with what velocity does it strike the ground? (round your answer to one decimal place.) m/s (d) if the stone is thrown downward with a speed of 2 m/s, how long does it take to reach the ground? (round your answer to two decimal places.) s