One is legitimate and the other is not.
Answer:
You want your product to be as strong and as long lasting as possible. There are also the safety implications to consider. You see, dangerous failures arising from poor material selection are still an all too common occurrence in many industries.
Explanation:
Answer:
Approximately
.
Explanation:
Make use of the fact that total momentum is conserved in collisions.
The momentum of an object of mass
and velocity
is
.
The momentum of the two trolleys before the collision would be:
.
.
Thus, the total momentum of the two trolleys right before the collision would be
.
Since the two trolleys are stuck to one another after the collision, they could modelled as one big trolley of mass
.
The momentum of the two trolleys, combined, is conserved during the collision. Thus, the total momentum of the new trolley of mass
would continue to be
shortly after the collision.
Rearrange the equation
to find the velocity of the two trolleys combined:
.
Answer:
Time to pass the train=0.05 h
How far the car traveled in this time=4.75 Km
Explanation:
We have that the train and the car are moving in the same direction, the difference between the speed of the vehicles is:

We will use this difference in the speed of the car an train to calculate how much time take the car to pass the train. For this we have that the train is 1km long and the car is moving with a speed of 20km/h (we use this value because is the speed that the car have in advantage of the train) then for a movement with a constant speed we have:

Where x is the distance, t is the time and v is the speed. using the data that we have:

This is the time that the car take to pass the train. Now to calculate how far the car have traveled in this time we have to considered the speed of 95Km/h of the car, then:

Answer:
Object 2 has the larger drag coefficient
Explanation:
The drag force, D, is given by the equation:

Object 1 has twice the diameter of object 2.
If 

Area of object 2, 
Area of object 1:

Since all other parameters are still the same except the drag coefficient:
For object 1:

For object 2:

Since the drag force for the two objects are the same:

Obviously from the equation above, c₂ is larger than c₁, this means that object 2 has the larger drag coefficient