A railroad hopper car is filled with sand and rolling with an initial speed of Vi on straight, horizontal tracks. You can ignore frictional forces on the railroad car. The total mass of the car plus sand is Mtotal. The hopper door is not fully closed, so that sand leaks out of the bottom. After some time t, mass M = 1 /4Mtotal has leaked out. What is the speed of the railroad car at time t?

u can delete ur account.

1. go on google and write

2 open this and click on your profile pic and if your profile is not appearing, then u have to log in.

3. when u click on your profile pic, there appears four options on the top.

4. click on the 1st option and scroll down and go at the bottom.

5. click on edit profile.

6. there appears a option 'prefernces' and at that option at the right side , 'edit' is written.

7. click on the edit option.

8. there is a option " i want to delete my account" and click on that.

hope this u

and ur welcm

: )