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.
Given:
Momentum of the dog (p) = 120.5 kg m/s
Speed of the dog (v) = 5 m/s
To Find:
Mass of the dog (m)
Concept/Theory:
![\underline{\underline{ \bf{\Large{Momentum}}}}](https://tex.z-dn.net/?f=%20%5Cunderline%7B%5Cunderline%7B%20%5Cbf%7B%5CLarge%7BMomentum%7D%7D%7D%7D)
- It is defined as the quantity of motion contained in a body.
- It is measured as the product of mass of the body and it's speed.
- It is represented by p.
- It's SI unit is kg m/s
- Mathematical Representation/Equation of Momentum:
![\boxed{ \bf{p = mv}}](https://tex.z-dn.net/?f=%20%5Cboxed%7B%20%5Cbf%7Bp%20%3D%20mv%7D%7D)
Answer:
By using equation of momentum, we get:
![\rm \longrightarrow m = \dfrac{p}{v} \\ \\ \rm \longrightarrow m = \dfrac{120.5}{5} \\ \\ \rm \longrightarrow m = 24.1 \: kg](https://tex.z-dn.net/?f=%20%5Crm%20%5Clongrightarrow%20m%20%3D%20%20%5Cdfrac%7Bp%7D%7Bv%7D%20%20%5C%5C%20%20%5C%5C%20%20%5Crm%20%5Clongrightarrow%20m%20%3D%20%20%5Cdfrac%7B120.5%7D%7B5%7D%20%20%5C%5C%20%20%5C%5C%20%20%5Crm%20%5Clongrightarrow%20m%20%3D%2024.1%20%5C%3A%20kg)
Mass of the dog (m) = 24.1 kg
A type of material that tries to prevent the flow of thermal energy is called an insulator.