Review It! Select the statement(s) that accurately describe kinetic energ, \( \square \) energy that is in motion \( \square \) skater at the top of the skate ramp \( \square \) roller coaster going down a hill \( \square \) energy that is stored \( \square \) skier skiing down a ski slope

The path of a sledder is shown; upon descending the hill, the sledder ultimately glides up a ramp to a final resting position (at D). Frictional forces can be assumed to be negligible. Givent mass = 34.0 kg ; Height at \( \mathrm{A}=7.0 \) meters, \( \$ \) peed at \( \mathrm{A}=6.4 \) \( \mathrm{~m} / \mathrm{s} \),

Review It! Select the statement(s) that accurately describe kinetic energ, \( \square \) energy that is in motion \( \square \) skater at the top of the skate ramp \( \square \) roller coaster going down a hill \( \square \) energy that is stored \( \square \) skier skiing down a ski slope

Мощность постоянного тока (в ваттах) вычисляется по формуле \( P=I^{2} R \), где \( I \) - сила тока (в амперах), \( R \) - сопротивление (в омах). Пользуясь этой формулой, найдите сопротивление \( R \), если мощность составляет \( 245 \mathrm{Bт} \), а сила тока равна 7 A . Ответ дайте в омах.

show that \( (u \times v) \bullet w=(v \times w) \bullet u=(w \times u) \bullet v \) 5. If \( u=2 i+4 j+8 k, v=2 i-3 j-6 k \) and \( w=5 i+4 j+8 k \) then show that \( (u \times v) \bullet w=(v \times w) \bullet u=(w \times u) \bullet v \)

3.31 - A "esteira rolante horizontal" do terminal de um aero- porto se move a \( 1,0 \mathrm{~m} / \mathrm{s} \) e tem \( 35,0 \mathrm{~m} \) de comprimento. Se uma mulher pisa em uma das extremidades e caminha a \( 1,5 \mathrm{~m} / \mathrm{s} \mathrm{em} \) relaçāo à plataforma móvel, de quanto tempo ela necessita para chegar à extremidade oposta, se andar (a) na mesma direção em que a plataforma se move? (b) Na direção oposta?