PIEAS Science General MCQs

Use the Pythagorean theorem for perpendicular components.
Magnitude = √(3²+4²)=5.

The x-component is A cosθ.
10 cos60° = 10×0.5 = 5.

The y-component is A sinθ.
10 sin30° = 10×0.5 = 5.

Vectors in the same direction add directly.
The resultant is 12+7 = 19 N.

Precision describes repeatability.
Measurements can be precise without being accurate.

Opposite collinear vectors subtract in magnitude.
The resultant magnitude is |12-7| = 5 N.

Accuracy describes agreement with the true or accepted value.
Systematic error can reduce accuracy.

Systematic errors often arise from calibration or method bias.
Repeated measurements do not automatically remove them.

Random errors cause scatter around a central value.
Repeated measurements and averaging can reduce their effect.

Leading zeros are not significant, but trailing zeros after a decimal are.
Thus 4, 5, and the final zero are significant.

The original total is 8 × 15 = 120.
After removing 22, the total is 98, and 98 ÷ 7 = 14.

The original total age is 4 × 25 = 100 years.
The new total is 5 × 27 = 135, so the new age is 35.