Acceleration | MCQs

Explanation

The weight of a man in an elevator descending with an acceleration of 4.9 m/s² will become:

Let:

• Actual weight $W=mg$

• Acceleration due to gravity g=9.8m/s^2

• Acceleration of the elevator a=4.9m/s^2

When an elevator descends with acceleration $a$, the apparent weight becomes:

W′=m(g−a)

Substitute values:

W′=m(9.8−4.9)=m(4.9)
W′=1​/2×mg

So, the apparent weight becomes half of the actual weight.

Explanation

The SI unit of acceleration is meters/second^2 (m/s^2 or ms^-2)

Acceleration (a) is defined as the rate of change of velocity.

Velocity is a vector quantity, and therefore acceleration is also a vector quantity.

Explanation

The slope of a velocity-time graph gives the rate of change of velocity, which is acceleration.

At any instant, this slope shows the instantaneous acceleration.

Explanation

In an oscillating pendulum, the bob accelerates from its extreme position due to the gravitational force acting on it.

The gravitational force pulls the bob towards the equilibrium position, causing it to accelerate.

Explanation

Near Earth's surface, the acceleration due to gravity (g) is approximately 10 meters per second squared (10 ms^-2).

This is a fundamental constant that describes the strength of gravity on our planet.