Practicing Success

Target Exam

CUET

Subject

Physics

Chapter

Laws of Motion

Question:

Which of the following is NOT true in the given context ?

A body of mass M is kept in a elevator which experiences free fall.

Options:

the body has acceleration g with reference frame attached to the earth's surface

the body has no acceleration at all with reference frame attached to the elevator

the resultant force on the body is zero with the reference frame attached to a car moving on the earth's surface with constant velocity

the resultant force on the body is zero with reference frame attached to the earth's surface

Correct Answer:

the resultant force on the body is zero with reference frame attached to the earth's surface

Explanation:

The body is in motion w.r.t. the elevator but falling with acceleration g w.r.t. the earth's surface. 

Car moving with a constant velocity i.e. zero acceleration acts as an inertial frame.