Answer:
 ∵
                                  ∵ 
Explanation:
The tangential acceleration of a cart moving at a constant speed in a circle is:
The angular velocity is constant when the circular speed is constant.
We know that the (instantaneous) tangential velocity of such object is given by:

Now for angular acceleration we have a constant angular speed:

And angular acceleration is related to tangential acceleration as:


 
        
             
        
        
        
Given: The number = 0.0069 that has to be expressed in scientific notation
Concept: When we express any number in scientific notation then we shall consider two points. 
(i) If we shift the decimal point from left to right after first (non-zero) digit then we count the number of shifted place of decimal and write them in terms of the negative power of 10. For example,  0.004789 = 4.789 ×10⁻³
(ii) If we shift the decimal point from right to left after first (non-zero) digit from the left end then we count the number of shifted place and write then in terms of the positive power of 10. For example,  4789.24 = 4.78924 ×10⁺³ = 4.78924 ×10³ Now, we shall convert the given number 0.0069 in scientific notation
0.0069  = 6.9 ×10⁻³ because we have shifted the decimal from left to right for three places that is after digit 6. 
Hence, the last option 6.9 ×10⁻³ will be the correct option. 
 
        
             
        
        
        
Weight. As a scientific term Weight is referred to as the force that Earth and objects have with each other. Your weight can be different on other planets.
        
                    
             
        
        
        
Answer:

Explanation:
The formula for force is: 

If we rearrange the formula to solve for a (acceleration), the formula becomes

The force is 68 Newtons. Let's convert the units to make the problem easier later on. 1 N is equal to 1 kg*m/s², so the force of 68 N is equal to 68 kg*m/s².
The mass is 2 kilograms. 

Substitute the values into the formula.

Divide. Note that the kilograms will cancel each other out (hence why we changed the units).


The acceleration is<u> </u><u>34 meters per second squared.</u>