Question

) a solid sphere of mass m and radius r is rolled down from an inclined plane of height 7 meter. The angle of inclination of the plane is 37°. What will be the speed of this sphere when it reaches the bottom of the inclined plane

Answer 1

Here first calculate the velocity of the sphere as it get the end of incline by putting mgh=1/2mv^2 we get v=root of 2gh putting values we get velocity =11.7m/s now calculate KE linear as 1/2mv^2...(1) all values are known and since it is rolling we have v=rw , angular KE 1/2Iw^2 replace w=v/r and I=2/5mr^2 for solid sphere we get 1/5mv^2....(2) add 1 & 2 and put v=11.7 , and get the answer.

In this I didn't get why they have given angle may be the given length is of the incline in that case by using the sine formula you can calculate the height and follow further as it is