一、原理:利用电唱机转盘匀速转动的特性,测出落体落至转盘平面唱盘转过的角度,从而得出落体自由下落的时间t,再利用公式g=2h/t~2求出g。二、结构:高度可调的木架、电磁铁、落体、取出盖面的电唱机、360等分分度盘、电子秒表、撞击开关、附可变电阻的电源(见图1) First, the principle: the use of turntable turntable uniform rotation characteristics, measured fall to turntable flat turntable turned angle, so as to get the free fall time t, and then use the formula g = 2h / t ~ 2 to find g. Second, the structure: height adjustable wooden frame, electromagnet, falling body, remove the cover of the record player, 360 subdivision dial, electronic stopwatch, impact switch, variable resistance power supply (see Figure 1)