Answer:
19.3
Explanation:
Assuming we have to find Specific gravity of gold.
As we know that specific gravity is defined as the ratio of weight of the object and weight of the water displaced by the object
so it is given by
specific gravity = weight of the object/weight of the water displaced
now we have
weight of the object = (density)(volume)g
weight of object = (19.3)(0.55)g
now weight of the liquid displaced is given by
weight of water displaced = (1 g/cm^3)(0.55ml)g
now we have
specific gravity = (19.3×0.55)/(1×0.55)
specific gravity= 19.3
Answer:
F'= 4F/9
Explanation:
Two small objects each with a net charge of +Q exert a force of magnitude F on each other. If r is the distance between them, then the force is given by :
...(1)
Now, if one of the objects with another whose net charge is + 4Q is replaced and also the distance between +Q and +4Q charges is increased 3 times as far apart as they were. New force is given by :
.....(2)
Dividing equation (1) and (2), we get :

Hence, the correct option is (d) i.e. " 4F/9"
It will be
d=m/v
=10/2
=5g/ml
Answer:
Explanation:
During the first .8 s , the elevator is under acceleration . It starts from initial velocity u = 0 , final velocity v = 1.2 m /s , time = .8 s
v = u + at
1.2 = 0 + .8 a
a = 1.2 / .8
= 1.5 m /s²
During the acceleration in upward direction , let reaction force of ground on man be R .
Net force on man = R - mg
Applying Newton's 2 nd law
R - mg = ma
R = m ( g + a )
= 72 ( 9.8 + 1.5 )
= 813.6 N .
This reaction force will be measured by spring scale , so reading of spring scale will be 813.6 N .
To calculate force, use the formula force equals mass times acceleration, or F = m × a. Make sure that the mass measurement you're using is in kilograms and the acceleration is in meters over seconds squared. When you've solved the equation, the force will be measured in Newtons.