Answer:
This is because the acceleration of objects due to gravity is independent of the mass of the object and is constant for all objects, therefore, all objects fall with the same speed.
Explanation:
The weight of an object or force of gravity acting on an object on the surface of earth is a product of its mass and acceleration due to gravity.
Mathematically, w = mg
where, m=mass of the object; g = acceleration due to gravity
Also, from newton's law of gravitation, gravitational force on the object ,F = GMm/r²
where G is the gravitational constant; M is mass of Earth; m is mass of object; r is the distance of separation between the object and the center of mass of the earth which is approximately the radius of earth.
Since the weight of an object is equal to the force of gravitation acting on it
W = F
mg = GMm/r²
g = GM/r²
The expression above is that of the relationship between the force of gravity acting on a body on the earth's surface, the weight of that body and the acceleration due to gravity, g.
It can be seen that the acceleration due to gravity g is independent of the mass of the object. Therefore, the acceleration of objects due to gravity is constant for all objects and all objects fall with the same speed.
The speed of bullet =
850 m/s
Distance given = 1 km = 1000m
S = D/t
t • S = D/t • t
St = D
St/S = D/S
t = D/S
t = 1000m/850m/s
t = 1.176 s
It will take the bullet 1.176 or about 1.18 seconds to go 1 km.
The answer would be D. Because the iron fillings are attracted to the magnet underneath the glass.
