Question

A small mass is suspended by a string from the ceiling of a car.As the car accelerates at a rate 'a' the string makes an angle theta with the vertical.Then the tension in the string

Answer 1

Answer:

Since, there is movement of the car, the string will accelerate thereby making some angles . let θ be the angles made by the string while moving from its original position to displaced position. On resolving the tension T, when it makes since and cosine components.

Vertical component is given by ,

Tcosθ=mg−−−(1)

Horizontalcomponentis

Tsinθ=ma−−−(2)

Squaringandadding(1)+(2).

T

2

cos

2

θ+T

2

sin

2

θ=m

2

a

2

+m

2

g

2

T

2

(cos

2

θ+sin

2

θ)=m

2

(a

2

+g

2

)

T

2

=m

2

(a

2

+g

2

)

T=m

(a

2

+g

2

)

Hence,optionDisthecorrectanswer.