The average speed of the car for the entire trip can be calculate by using:
where S is the total distance covered by the car, and t is the total time taken.
The total distance travelled by the car is:
while the total time taken is:
so, the average speed of the car is:
so, the correct answer is (3) 85 km/h.
Answer:
Explanation:
A unit used to measure a vector quantity is the
c) Newton
Answer:
1. The magnet is magnetic and can attract iron articles.
2. The magnet has magnetic poles. Each magnet has two kinds of poles: N pole and S pole. They are in pairs.
3. Temporary magnet and permanent magnet: when the ferromagnetic material is magnetized, it is easy to lose the magnetic property, which is called temporary magnet (for example: iron); when the ferromagnetic material is magnetized, it is not easy to lose the magnetic property, which is called permanent magnet (for example: steel).
4. When two magnets are close to each other, the same poles will repel and push away from each other, and the different poles will attract and stick to each other. Therefore: the same pole repels each other, the different pole attracts each other.
5. The attraction of a magnetic object is called magnetism. An object is surrounded by a magnetic material. The area affected by the magnetic force is called the magnetic field.
