Answer: C
Explanation:
A bird flying in the air is 3D motion as the bird move up, down, right, left all the possible direction. A leaf falling from a tree is also a 3D motion because a leaf never fall in absolute vertical manner. A lady bug crawling on a soccer ball also 3D. If lady bug crawling on a plane like floor then it is 2D but now lady bug crawling on soccer ball which is in spherical shape so it is also 3D motion. Only train travelling along a track is 2D because train cannot move up and down and the track of train is in a plane. So it is 2D motion.
Answer:
11.1 m/s
Explanation:
120 km = 120 x 1,000 = 120,000 m
3 hours = 3 x 60 x 60 = 3600 x 3 = 10,800 s
speed = 120,000 / 10,800
= 1200/108
= 11.1 m/s
Answer:
The density of the metal is 5200 kg/m³.
Explanation:
Given that,
Weight in air= 0.10400 N
Weight in water = 0.08400 N
We need to calculate the density of metal
Let 
be the density of metal and 
be the density of water is 1000kg/m³.
V is volume of solid.
The weight of metal in air is
.....(I)
The weight of metal in water is
Using buoyancy force
We know that,
....(I)
Put the value of 
in equation (I)
Put the value of Vg in equation (II)
Hence, The density of the metal is 5200 kg/m³.
