Asmall sphere hangs from a string attached to the ceiling of a uniformly accelerating train car. it is observed that the string makes an angle of 37° with respect to the vertical. the magnitude of the acceleration a of the train car is most nearly?

a=7.384 m/s^2

Explanation:

let T be the tension in the string, m= mass

and a= acceleration

from the FBD in the attachment we can write

Tcos37°= mg

Tsin37° =ma

dividing both the equations we get

tan37° =a/g

therefore a=g×tan37°

a= 9.81×0.7535 = 7.384 m/s^2

the  magnitude of the acceleration a of the train = 7.384 m/s^2

he made 11 calls in one day