Pakistan MCQs

The first law describes inertia.
A net external force is required to change velocity.

For constant mass, Newton's second law becomes F=ma.
It links net force to acceleration.

Interaction forces occur in pairs on different bodies.
They are equal in magnitude and opposite in direction.

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

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

The newton is derived from base units as kg·m/s².
Metre, kilogram, and second are base units.

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.

Displacement is a vector from initial to final position.
It can be zero even when distance traveled is not zero.

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