1.
A spring has a
spring constant of k = 55.0 N/m. The
spring is compressed
3.50 cm. What is the PE
stored in spring?

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2.
An 85 g wooden
block is set up against a spring. The
block rests on a smooth surface. The
block is pushed into the spring, compressing it a distance of 2.0 cm and then
released. The spring constant is k = 78
N/m. What is the speed of the block when
it reaches its initial position (where the spring was not compressed)?

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3. A roller coaster starts at
some height that you do not know. It
goes down this hill and then goes up a second hill that is 28.5 m above the
first drop. So how high was the initial
hill?

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4.
A 5.0 kg crate
slides down a smooth ramp that is elevated at an angle of 38°. The length of
the ramp is 2.0 m. What will be the
speed of the crate at the bottom of the ramp?

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5.
A fireman runs up
a 7.5 m ladder. The fireman has a mass
of 52 kg and is carrying 15 kg of firefightin’ gear. If the fireman developed 685 watts, how much
time did it take to reach the top of the ladder?

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6. A 3.00 kg mass, *m _{1}*

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(b)
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(c)
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7. A
3.12 kg iron ball is suspended from the ceiling of a room by two cords as shown
in the drawing. The ceiling is 2.20 m
above the deck. The angle ** q** is 61.0°. The other cord is perfectly horizontal. Find (a) The tension
in both strings. (b) The potential
energy of the ball relative to the deck.
(c) if the horizontal spring were to break,
what would be the velocity of the ball when the other cord is vertical?

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(b) _{}_{}

(c) _{}

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8. A 47.0 kg projectile is launched with an initial speed of 72.0 m/s and an angle of 39.8° above the horizontal. The projectile lands on a hillside 7.15 s later. Neglect air friction. (a) What is the projectile’s kinetic energy at the highest point of its trajectory? (b) What is the height of the impact point? (c) What is its total energy just before it hits the hillside?

(a) _{}

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(b) _{}

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(c) *Energy
at impact point is same as when it was fired.*

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