Một vật khối lượng m được kéo trượt trên sàn bằng lực kéo F tạo góc α so với phương ngang. Biết hệ số ma sát với sàn là µ.
a. Tìm gia tốc của vật với α = 0, µ = 0,01, m = 1kg, F = 2N
b. Với α = 0, µ = 0,01, m = 1kg, muốn vật đi đều thì F = ?
c. Với α = 0, µ = 0,01, m = 1kg, muốn vật sau khi xuất phát 50m có vận tốc 36 km/h thì F = ?
d. Tìm gia tốc của vật khi α = 300, µ = 0,01, m = 1kg, F = 2N.

answer: the metamorphic rocks are formed when they are exposed to high pressure and high temperatures. this happens when one of the earth's plates comes in contact with the other plate by traveling in opposite directions, straight into each other or slipping under one another. the friction that is caused by this activity results in   melting of rocks and when it cools they are known as metamorphic rocks. this process needs a controlled amount of pressure and temperature otherwise it may turn into magma.

the old price per ounce is c/4.

the new price per ounce is c/3.6.

the ratio of the old price to the new one is

(c/4)/(c/3.6) = (c/c)×(3.6/4) = 0.9 . . = 9/10 . . "nine tenths" in either form

myth. it was once thought that animals, including cats and dogs, could only see in black and white. however, scientists have proven this to be a myth. in all animals, including humans, the perception of colour is determined by the presence of cells in the eye called cone photoreceptors.