課程名稱︰普通物理學丙
課程性質︰
課程教師︰葉平老師
開課系所︰物理系
考試時間︰2004/11/10
試題 :(這是開給森林系的課)
1.(10)Use your won words to describe th Work-Energy Theorem, and what law(s) lead
to the theorem.
2.(24)A model rocket is fired straight up from ground level with a constant
accelation of 40m/s^2 until the engine runs out of fuel after 5s. Negletcting
air resistance, find
A. the hight of the rocket when the engine stops;
B. the maximum height reached;
C. the total time duration of the flight.
3.(10)You are designing a race track. To ensure safely to the audience and the
driver, the radii of turns must not be too small. However, the race is more
exciting if there are some sharp turns.Suppose the race cares are making
uniform circular motions while turning, and the driver can endure 3gees of
accelation at most, and the fastet race car reaches a speed of 300km/hr, what
is the minimum radius of a turn?
4.(24)A 50-kg wiman climbs a mountain 3000m high.
A. How much work does she do against gravitational forces?
B. A kilogram of fat supplies about 3.8*10^7 J of energy. If she converts fat
in to mechanical energy with a 20 percent rate, how much fat will she consume
in the climb?
C. When she came down from the mountain to the ground slowly and safely, what
happens to the work done by the gravitaional force on her?
5.(24)As figure. The mass m1 is on a slope with incination angle b. A string
connects it to a pulley with mass m2 and another mass m3 and finally is tied
to the ceiling. The slope has a coefficient of kinetic friction 0.2. Neglect
the air resistance.
| 右邊是個動滑輪裝置，滑輪質量m2，下方懸吊物質量m3；
/\ | 左邊是個平放在斜面上的物體質量m1，我沒辦法畫的更清晰了>"<
/ | | 在斜面上還有一個定滑輪(沒有畫出來)，繩子跨過定滑輪。
/ ◢ | |
m1 ▆◢◢ |○| m2
◢◢◢ |
◢◢◢◢ █ m3
◢◢◢◢◢
◢◢◢◢◢◢
A. Draw the free body diagrams for m1,m2, and m3.
B. Write down the force equations and find the acceleration of m1 expresssed
in terms of all the masses and the inclination angle b.
C. Take m1= 2kg, m2= 0.5kg, m3= 4kg, cos(b)=0.6,fine the tension on the
string that connects m2 and m3.
6.(8) The average center-to-center distance from the earth to the moon is
3.84*10^5 km. The mass of the moon is approximately 0.012 times of the mass
of the earth. What is the distance from the center of the moon at which
the graviaional potential energiesof the earth and moon are equal?
--
話說得太大，書看得太少，這就是問題所在。
--
※ 發信站: 批踢踢實業坊(ptt.cc)
◆ From: 140.112.193.113