Consider a cart being pulled by a horse with a constant velocity. The horse exerts force `vecF_(C//h)` on the cart. (The subsript indicates the force on the cart due to the horse). The first subscript denotes the body on which the force acts and the second due to which it acts.

Choose the correct statement (s):

Options

A. `vecf((C )/(g))`,`vecN_((C )/(g))`,`vecN_((h)/(g))` are externel forces on a system consisting of horse and cart.
B. `vecF_((h)/(g))+vecf_((C )/(g))=0`
C. `vecN_((C )/(g))` and `vecF_((C )/(E))` are action reaction pairs
D. `vecF_((C )/(h))` and `vecf_((h)/(C ))` are action reaction pairs

Answer

A, B, D

Explanation

(a) For the system of (horse`+`cart), only `vecF_((c )/(h))` and `vecF_((h)/(c ))` will be internal forces. All other forces will be external.
(b) As (horse`+`cart) system is moving with constant velocity, so net horizontal force on it should be zero.
For this `vecF_((h)/(g))+vecF((c )/(g))=0`
(c ) `vecN_((C )/(g))` and `vecF_((C )/(E))` can't bbe action-reaction pairs, as they act on same body.
(d) `vecF_((C )/(h))` and `vecf_((h)/(C ))` are action-reaction pairs.