PIEAS Pre Medical MCQs

Perpendicular vector components form a right triangle.
The resultant magnitude is found from the sum of squared components.

One kilometre equals 1,000 metres.
Therefore 3.5 km = 3.5×1,000 = 3,500 m.

One metre equals 100 centimetres.
Therefore 250 cm ÷ 100 = 2.5 m.

Percentage uncertainty is absolute uncertainty divided by measured value times 100.
0.2/10.0×100 = 2%.

Percentage error is |48-50|/50×100.
The result is 2/50×100 = 4%.

Move the decimal four places to the right to obtain 7.2.
Therefore the exponent is -4.

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.

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.