Question

Q.5 Object A has 27 J of kinetic energy. Object B has one-quarter the mass of object A. (2 Marks)

(a) If object B also has 27 J of kinetic energy, is it moving faster or slower than object A & by what

factor?

(b) By what factor does the speed of each object change if total work -18 J is done on each?


Q.6

(a) Deduce relationship between Commercial unit of energy and SI unit of energy. (1 Mark)

(b) If an object initially at rest at point A is slightly pushed towards right Calculate the object’s

velocity at point B.

Answer 1

Answer:

a) Object B is moving faster

Explanation:

a) Object B is moving faster bcz

we know, KE= 1/2 mv^2

now , m¹v¹= m²v²

mv¹= m/4 v²

v²= 4v¹

B) we know that,

work done = change in ke

-18= 1/2( mvv- m/4* 16vv)

-36= -3mvv

mvv = 12