PHY 101 Mock Test 1

All points on a rigid rotating body share the same angular displacement, velocity, and acceleration. Linear quantities depend on radius (v = rω, a_c = rω²)..

Dimensionally: [ML⁻¹T⁻²] = [ML⁻³]ᵃ [LT⁻¹]ᵇ. Solving gives: For M: 1 = a; for L: -1 = -3a + b → b=2; for T: -2 = -b → b=2.

This is the operational definition: a frame where an object with no net force acting on it moves with constant velocity (or remains at rest).

With no horizontal force, the horizontal component of velocity remains unchanged. The vertical acceleration is always -g downward.

A world line on a space-time plot shows an object’s position (space) at every moment (time).

Rotational KE = (1/2)Iω². KE is proportional to ω², so doubling ω increases KE by a factor of 2² = 4.

An event is a fundamental concept defined by its spatial coordinates (x, y, z) and its time coordinate (t).

This principle asserts that the fundamental laws of motion are invariant (take the same form) for all observers moving with constant velocity relative to each other.

It does not exchange matter or energy with its surroundings.
Explanation: An isolated system has no interactions across its boundary, no transfer of mass, heat, or work.

This is the definition of a perfectly elastic collision.

Displacement has both magnitude (distance) and direction. Temperature, mass, and time are scalars with magnitude only.

By definition, P_total = Σ (m_i * v_i) for all particles i.

It is the mass-weighted average position of all particles in the system. It can lie outside a physical object (e.g., a doughnut).

The first law introduces the property of matter known as inertia, which is the tendency of an object to resist changes in its state of motion.

Impulse, J = ∫ F dt (or F_avg Δt for constant force), is a measure of the change in momentum it produces.

By definition, the normal force is the component of contact force perpendicular (normal) to the surface. Its magnitude depends on the situation.

The law of conservation of momentum states that the total momentum of an isolated system remains constant. Mechanical energy is only conserved if non-conservative forces do no work.

The center of mass of any system under the influence of a uniform gravitational field follows the simple parabolic trajectory of a point mass.

v_AB = v_A – v_B = (60 N) – (80 N) = -20 N, which is 20 km/h in the opposite direction (South).

The ball has the train’s initial horizontal velocity relative to the ground. Under gravity alone, it follows projectile motion (a parabola) as seen by the ground observer.