Ablock of gold has dimensions of 2 cm by 10 cm by 4 cm and its density is 19.3 g/cm3. what is the mass of this block of gold?

Zeros that follow non-zeros numbers and are also to the right of a decimal point are significant

What is the electric force acting between two charges of -0.0045 c and -0.0025 c that are 0.0060 m apart? use fe=kq1q2/r^2 and k = 9.00 x 10^9 n*m^2/c^2 a. 1.7 x 10^7 n b. -1.7 x 10^7 n c. -2.8 x 10^9 n d. 2.8 x 10^9 n

Can anybody me with this? ? (picture included.)