Question

数学难题>,<

1.(a)
Let D = Distance moved by object
M = Mass of object in kilograms ( 1 kh = 10 N )
W = Work done on the object

Relate D , M and W in an equation .
1.(b)
Calculate in kilojoules the amount of work done when a bus of 10 tonnes moves 100 metres along a level road . (1 tonne = 1,000 kg )

2.(a)
Mrs kumar climbs up a flight of 28 steps to reach a temple . Each step is 20 cm high. Mrs Kumar weighs 600 N . Caculate the work done by Mrs Kumar .

2.(b)
She eats a small plum given to her by the priest . The plum provides 200kJ of energy . How many steps can she climb using this amount of energy ?

能做多少就多少，拜托啦～

Answer 1

重力势能:Ep = mgh (与零势能面的选择有关)
1（a）W=MgD
1（b）W=10000kg*10*100m
19, 功 : W = Fs cos (适用于恒力的功的计算)
2 （a）W=FS=600N*0.28m*28
2（b）W=200KJ Steps=200KJ/600N/0.28m
……居然做全英的物理题……我都快忘光了

Answer 2

They're not math problems, but physics ones.
1. W=pMD ; p is a coefficient with unit N/kg. It may be p=10N/kg according to your problem.
2.(a) W=FD=600N * (28 * 0.2)m = xx J
2.(b)E=200kJ. D=E/F=200kj/600N.
let a=0.2m/step. number of stpes Mrs Kumar can climb S=D/a.
substitute the data can calculate the result all by yourself, plz.