(a) The diagram shows a man pulling a child on a sledge. The mass of the child and sledge is 45kg.

The unbalanced force acting on the sledge is 49N.

(i) State the equation linking unbalanced force, mass and acceleration.

(1)

(ii) Calculate the acceleration of the child and sledge.

How is coal extracted from mountaintop removal mines? a. dynamite is used to create underground tunnels where miners go to extract the coal. b. dynamite is used to break apart rocks and then draglines are used to remove the broken rock and reach the coal. c. coal in mountaintops is extracted by digging strips in the landscape to reach the coal. d. placer deposits in mountain river bottoms are removed by

Which compound is held together by the electrostatic force between two ions? a. co2 b. cci4 c. h2s d. mgf2

The radius of an atom is closest in size to a