Which of the following is a correct equation of motion for uniformly accelerated motion?
Analysis & Theory
v = u + at is one of the standard equations of motion.
Acceleration due to gravity (g) on Earth is approximately:
Analysis & Theory
Standard value of g ≈ **9.8 m/s²** near Earth's surface.
At the highest point of vertical projection, the vertical velocity becomes:
Analysis & Theory
At the highest point, **vertical velocity = 0**.
Time of ascent of a vertically projected body is given by:
Analysis & Theory
Time of ascent T = **u/g** where u = initial velocity.
Maximum height reached in vertical projection is given by:
Analysis & Theory
**Maximum height** H = **u² / 2g**.
For a horizontal projection, what is the vertical velocity after time t?
Analysis & Theory
Vertical velocity increases with time: **v = gt**.
What is the time of flight for a projectile projected at angle θ with speed u?
Analysis & Theory
**Time of flight** = 2u sinθ / g.
What is the expression for **horizontal range** of a projectile?
Analysis & Theory
Horizontal range R = **(u² sin2θ) / g**.
On reaching the projection point in projectile motion, the velocity of the object is:
Analysis & Theory
It regains the **same magnitude of speed** but in the **opposite direction**.
Frictional force always acts:
A
In the direction of motion
B
Perpendicular to motion
C
Opposite to direction of motion
Analysis & Theory
Friction always **opposes** the motion.
What is the relation between limiting friction (F) and normal reaction (R)?
Analysis & Theory
**F = μR** where μ is the coefficient of friction.
The angle of friction (θ) is related to μ by:
Analysis & Theory
tan(θ) = **μ**.
Which of the following **reduces friction**?
Analysis & Theory
**Lubrication** with oil/grease **reduces friction**.
What is a **disadvantage of friction**?
Analysis & Theory
**Disadvantage**: friction causes **energy loss** through heat and wears out surfaces.
On a **smooth inclined plane**, what is the only force causing acceleration?
C
Component of weight parallel to incline
Analysis & Theory
**Component of weight** along the incline (mg sinθ) causes acceleration.
If a body slides down a rough incline, friction acts:
C
Perpendicular to incline
Analysis & Theory
Friction always **opposes motion**, so it acts **up the plane**.