Answer:11 km/s
Explanation:
Given
Escape velocity at the surface of earth is 11 km/s
Escape velocity is given by
Escape velocity at the surface of earth
--------------------1
If Escape velocity is three times and the radius is also the three times
i.e. 
Models help us to understand systems and their properties
Answer:
T = 25 N
Explanation:
The question says that "A 25 n block is suspended by a wire from the ceiling vitamin the tension that appears in the wire
?"
Weight of the block, W = 25 N
Weight of a body acts in downward direction and tension acts in upward direction. It would mean that,
Tension = weight of the block
T = mg
T = 25 N
Hence, the tension in the wire is 25 N.
Consider a long train moving at speed v. Now consider a passenger throwing a ball inside this train, towards the back of the train, with same velocity v (but in the opposite direction of the train movement).
- A passenger inside the train will see the ball moving with speed v
- For an observer outside the train, however, the ball will appear as still. In fact, for him the ball will have a speed v (given by the movement of the train) -v (velocity of the ball but moving in the opposite direction), so the net velocity will be v+(-v)=0.
