1. Kei tētahi mea te Tuhinga o mua o te 1 kg m2 hurihuri i te tere koki pumau o 2 rāti/hēkona. He aha te mea te pūngao nekeneke hurihuri o te mea?
Mōhiotia:
Te wā o te korekore (I) = 1 kg m2
te tere nekehanga (ω) = 2 rāti/hēkona
Hiahia: Te pūngao nekeneke hurihuri (KE)
Rongoā:
Ko te tātai o te pūngao nekeneke hurihuri:
KE = 1/2 ahau ω2
KE = te pūngao nekeneke hurihuri (kg m2/s2), ahau = te wā o te korekore (kg m2), ω = te tere koki (rad/s)
Te pūngao nekeneke hurihuri:
KE = 1/2 I ω2 = 1/2 (1)(2)2 = 1/2 (1)(4) = 2 Joule
2. He 20-kg pūwero rango me te radius o te 0.2 m ka huri i te tere koki pumau o te 4 rad/s. He aha te kaha nekeneke hurihuri o te pūrakau?
Mōhiotia:
Mass o te pūrakau rango (M) = 20 manog
Te pūtoro o te rango (r) = 0.2 mita
Te tere koki (ω) = 4 rad/s
E hiahiatia ana: He aha te pūngao nekeneke hurihuri
Otinga;
Te tātai o te wā o te korekore o te rango:
I = 1/2 mr2
Ahau = te wā o te korekore (kg m2), m = papatipu (kg), r = pūtoro (mita)
Te wā o te korekore o te pūrakau rango:
I = 1/2 (20)(0.2)2 = (10)(0.04) = 0.4 kg m2
Te pūngao nekeneke hurihuri o te pūrakau:
KE = 1/2 I ω2 = 1/2 (0.4)(4)2 = (0.2)(16) = 3.2 Joule
3. A-10 kg pōro me te radius o 0.1 m hurihuri i te tere pumau o 10 rāti/hēkona. He aha te pūngao nekeneke o te pōro.
Mōhiotia:
Mass o te pōro (M) = 10 kg
Te whānui o te pōro (r) = 0.1 mita
Te orite angular (ω) = 10 rpānuitanga
E hiahiatia ana: Te pūngao nekeneke hurihuri
Rongoā:
Te tātai o te wā o te korekore:
I = (2/5) Mr.2
Ahau = Tuhinga o mua (kg m2), m = papatipu (kg), r = pūtoro (M)
Te wā o te korekore o te pōro:
I = (2/5)(10)(0.1)2 = (4)(0.01) = 0.04 kg m2
Te pūngao nekeneke hurihuri o te pōro:
KE = 1/2 I ω2 = 1/2 (0.04)(10)2 = (0.02)(100) = 2 Joule
4. A 0.5-ka huri ngā matūriki kg i te tere koki pumau o 2 rāti/hēkona. He aha te pūngao nekeneke hurihuri o te matūriki mēnā ko te radius o te porowhita 10 cm.
Mōhiotia:
Mass o te matūriki (M) = 0.5 manog
Te pūtoro o te pōro (r) = 10 henimita = 10/100 = 0.1 mita
Te tere koki (ω) = 2 rāti/s
E hiahiatia ana: Te pūngao nekeneke hurihuri
Rongoā:
Te wā o te korekore mō ngā matūriki:
I = Mr.2 = (0.5)(0.1)2 = (0.5)(0.01) = 0.005 kg m2
Te pūngao nekeneke hurihuri:
KE = 1/2 I ω2 = 1/2 (0.005)(2)2 = 1/2 (0.005)(4) = (0.005)(2) = 0.01 Joule
