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Solving Physics Exercise 10: Momentum. Law of Conservation of Momentum
Exercise 1 (page 126 Physics Textbook Grade 10)
Define and explain the significance of momentum.
Solution guide:
+ Definition of momentum:
Momentum of an object with mass m moving at velocity v is defined by the formula:
P→ = m.v→
+ Significance of momentum: it describes the relationship between mass and velocity of an object during mechanical interaction. Therefore, momentum characterizes the dynamic state of an object.
Exercise 2 (page 126 Physics Textbook Grade 10)
When does the momentum of an object change?
Solution guide:
When a sufficiently strong force acts on an object for a finite period of time, it can cause a change in the momentum of the object.
Exercise 3 (page 126 Physics Textbook Grade 10)
What is an isolated system?
Solution guide:
An isolated system is a system where only the objects within the system interact with each other (known as internal forces) and the internal forces act pairwise. In an isolated system, there are no external forces acting on the system, or if there are external forces, they balance each other out.
Exercise 4 (page 126 Physics Textbook Grade 10):
Solution Guide:
Exercise 6 (page 126 Physics textbook Grade 10)
A ball flying horizontally with momentum p strikes perpendicularly against a vertical wall, rebounds backward with a velocity of equal magnitude but opposite direction to its initial velocity. The change in momentum of the ball is:
Choose the correct answer.
Exercise 7 (page 127 Physics textbook Grade 10)
A small object with mass m = 2 kg slides down a smooth incline at a certain moment with a velocity of 3 m/s, then after 4 s it has a velocity of 7 m/s, immediately after which, for the next 3 s, the object has momentum (kg.m/s) of:
Answer:
- Choose C.
- The acceleration of the object is:
Exercise 8 (page 127 Physics textbook Grade 10):
Car A has a mass of 1000 kg and a velocity of 60 km/h; car B has a mass of 2000 kg and a velocity of 30 km/h. Compare their momenta.
Solution Guide:
Exercise 9 (page 127 Physics textbook Grade 10):
A plane has a mass of 160000 kg, flying at a speed of 870 km/h. Calculate the momentum of the plane.
