[د.امير]

Q1:- The centers of two 10 kg spheres are separated by 0.1m. what is their gravitational attraction
The gravitational force of two bodies of mass m1 and m2 and separated by a distance L is
Fg is proportinal to (m1*m2)/(L^2)
or Fg= G *(m1*m2)/(L^2)
where G is the gravitational constant =6.67E-11 N.m^2/kg^2
In this case the mass of the two spheres are 10kg
Then Fg = 6.67E-11*(10 x 10) / (0.1m^2) = 6.67E-7 N


Q2 :- A woman exerts a constant horizontal force of 200 N on a child and a tricycle. The tricycle moves 2m. and the work done by the woman is 100 J . What is the angle between the force and the displacement of the tricycle

Work =Force x distance x cos (theta),
100 joule = 200N x 2m cos (theta),
Cos (theta) = 1/4
Or theta =60