Answer:
Speed of the helium after collision = 246 m/s
Explanation:
Given that
Mass of helium ,m₁ = 4 u
u₁=598 m/s
Mass of oxygen ,m₂ = 32 u
u₂  = 401 m/s
v₂ =445 m/s
Given that initially both are moving in the same direction and lets take they are moving in the right direction.
Speed of the helium after collision = v₁
There is no any external force on the masses that is why the linear momentum will be conserve.
Initial linear momentum = Final linear momentum
P = m v
m₁u₁+m₂u₂ = m₁v₁+m₂v₂
598 x 4 + 32 x 401 = 4 x v₁+ 32 x 445
v₁ = 246 m/s
Speed of the helium after collision = 246 m/s
 
        
             
        
        
        
We have that for the Question "the acceleration of the object at time t = 0.7 s is most nearly equal to which of the following?"
-  it can be said that the acceleration of the object at time t = 0.7 s is most nearly equal to the slope of the line connecting the origin and the point where the graph where the graph crosses the 0.7s grid line
From the question we are told 
the acceleration of the object at time t = 0.7 s is most nearly equal to which of the following?
Generally the equation for the Force  is mathematically given as
F=\frac{F}{dx}
Therefore
F=-kdx
k=600Nm^{-1}
now 
K.E=0.5x ds^2
K.E=600*(-0.1^2)
K.E=3J
Therefore
the acceleration of the object at time t = 0.7 s is most nearly equal to the slope of the line connecting the origin and the point where the graph where the graph crosses the 0.7s grid line
For more information on this visit
brainly.com/question/23379286
 
        
             
        
        
        
Answer:
270 mi/h
Explanation:
Given that,
To the south, 
v₁ = 300 mi/h, t₁ = 2 h
We can find distance, d₁

To the north, 
v₂ = 250 mi/h, d₂ = 750 miles
We can find time, t₂

Now,
Average speed = total distance/total time

Hence, the average speed for the trip is 270 mi/h.
 
        
             
        
        
        
Answer:
1.93 x 10∧3 N
Explanation:
The picture attached shows the calculation
 
        
             
        
        
        
Answer:   Idk I think I forgot
Explanation: