Askier starts from rest at the top of a 40.8 m hill, skis down a 30 degree incline into a valley, and continues up a 32.5 m high hill. the heights of both hills are measured from the valley floor. assume that you can neglect friction and the effect of the ski poles. how fast is the skier moving at he bottom of the valley? what is the skier's speed at the top of the next hill? do the angles of the hills affect your answers?

a. 28.27 m/s

b. 12.75 m/s

c. No

Explanation:

a.

The bottom

Ek = Ep

¹/₂ * m * v² = m * g * h₁

v = √ 2 * g * h₁  = √ 2 * 9.8 * 40.8 m

v = 28.27 m/s

b.

At the top

Ek = Ep

¹/₂ * m * v² = m * g * h₁

v = √ 2 * g * h₁  = √ 2 * 9.8 * (40.8 - 32.5) m

v = 12.75 m/s

c.

No in this case the axis is the same of the motion so, the angle doesn't affect the result

gpe = mass x gravity constant x height or… gpe = mgh

where… mass: measured in kilograms (kg)

gravity: gravity constant on earth = 10.00 m/s2

height: measured in meters (m)

gpe: measured in joules (j) or kilojoules (kj)

how do you solve gpe?

gravitational potential energy (gpe) is the energy an object has because of its position above the. ground.

gpe = mass x gravity constant x height or… gpe = mgh.

mass:

note: to earn full marks when solving science word problems, you must show your work:

formula.

example:

given values:

mass = 0.3 kg.

pythagoras' theorem

square root (-5^2+9^2)

square root (25+81)

square root (106)

angle is tan^-1(9/5)

neg x, pos y