Question

A particle moves east wards with constant speed 10m/s and after travelling for 20 m it takes 90 degree left turn without change in speed ,it travels for another 20 m in straight line ,find avg.Accelaration for entire mition

Answer 1

here we should use vector concept.

A particle moves eastwards with constant speed 10m/s and travels 20m.

so, initial velocity of particle , u = 20i m/s displacement of particle in East direction , s = 20i

after travelling for 20m, it takes 90° left turn without change in speed. means, now particle moves north direction with speed 10m/s .

time taken to move 20 m east = 20/10 = 2 sec

so, final velocity of particle , v = 10j m/s

and then moves 20m in straight line.

so, displacement of particle in North direction , s' = 20j m/s

time taken to 20m north = 20/10 = 2sec

so, total time taken during motion = 2 + 2 = 4sec

using Newton's 1st equation of motion,

v = u + at

a = (v - u)/t

= (10j - 10i)/4

= 2.5j - 2.5i

and magnitude of acceleration, |a| = √{6.25 + 6.25} = √{12.5} = 3.53 m/s²