To calculate the of a moving object, divide the displacement by the time interval in which the displacement occurred.

Speed

Explanation: Scalar quantity is the quantity that only possess magnitude but no direction.

Vector quantity is the quantity that only possess magnitude as well as  direction.

Speed is defined as the displacement of an object per unit time and is a scalar quantity as it does not involve any direction.

Velocity is defined as the distance moved by an object per unit time and is a vector quantity as it deals with magnitude as well as direction.

answer: 2×10^-2kg

explanation: density= mass per volume

vol=mass/density

converting to s.i units we have;

3÷1000kg = 0.003

1.5÷100m = 0.15

0.003/0.15 = 0.02kg