A train is moving along a straight section of the track at a constant speed. Which of the following statements about the train is true. a). If the train is moving at a constant speed, there must be no forces at all acting on the train.

b). If the train is moving at a constant speed, then any forces that might be acting on the train must cancel out.

P. s-The subject is actually science topic: forces review

c). There must be an unbalanced force acting on the train to keep it moving.

d). The train must have a force acting on it larger than the train's inertia in order to keep moving.

1. suppose a reaction mixture, when diluted with water, afforded 300 ml of an aqueous solution of 30 g of the reaction product malononitrile [ch2(cn)2], which is to be isolated by extraction with ether. the solubility of malononitrile in ether at room temperature is 20.0 g/100 ml, and in water is 13.3 g/100 ml. what weight of malononitrile would be recovered by extraction with (a) three 100-ml portions of ether and (b) one 300-ml portion of ether? suggestion: for each extraction, let x equal the weight extracted into the ether layer. in part (a), the concentration in the ether layer is x/100 and in the water layer is (30 x)/300; the ratio of these quantities is equal to k 20/13.3.

How many oxygen atoms are there in 3.15 moles of hcl manganese (iv) oxide, mno2

Akno3 solution containing 51 g of kno3 per 100.0 g of water is cooled from 40 ∘c to 0 ∘c. what will happen during cooling?