a body lying initially at point [3,7] starts moving with a constant acceleration

Question

of 4i^{^} . if the position after 3 secs is given by the coordinates :

[a] [7,3]

[b] [7,18]

[c] [21,7]

[d] [3,7]

Answer 1

Correct option(c)

Explanation:

The initial co ordinate of the particle is (3,7) 

Initial x co ordinate is 3 units. 

Initial y co ordinate is 7 units 

As the body starts from rest so its initial velocity is zero. 

The acceleration of the body along x axis is 4 units 

The acceleration of the body along y axis is 0 

So after 3 seconds, using equation of motion, along x axis x = x₀ + ut + at² /2 

or as u  = 0 and a  = 4 units t = 3 seconds 

substituting we get, 

s = 3 +  (4 x 3²)/2  = 21 units 

As there is no motion along y axis so it will remain unchanged. 

Hence the final co ordinates are  : (21,7)

Comments

thanks a lot didi / swara