NEETPhysicsLaws of Motion
Given below are two statements: Statement-I: An elevator can go up or down with uniform speed when its weight is balanced with the tension of its cable. Statement-II: Force exerted by the floor of an elevator on the foot of a person standing on it is more than his/her weight when the elevator goes down with increasing speed. In the light of the above statements, choose the correct answer from the options given below:
Options
- ABoth Statement I and Statement II are false
- BStatement I is true but Statement II is false
- CBoth Statement I and Statement II are true
- DStatement I is false but Statement II is true
Correct answer
B. Statement I is true but Statement II is false
Step-by-step solution
When elevator is moving with uniform speed T = F g , as the net force along the vertical direction should be zero. Therefore, Statement-I is true. Now, when elevator is going down with increasing speed, its acceleration is downward. Hence, W - N = m a ⇒ W - N = W g × a ⇒ N = W 1 - a g Clearly, normal reaction is less than weight. So Statement-II is false.