ur answer is A or also known as 
When you push a child on a swing, you are doing work on the child because  you are pushing against the force of gravity
hope this helps :)
 
        
                    
             
        
        
        
We can use the ideal gas equation which is expressed as PV = nRT. At a constant volume and number of moles of the gas the ratio of T and P is equal to some constant. At another set of condition, the constant is still the same. Calculations are as follows:
T1/P1 = T2/P2
P2 = T2 x P1 / T1
P2 = 273 x 340 / 713
<span>P2 = 130 kPa</span>
 
        
             
        
        
        
Impulse = change in momentum
The car's momentum was (mass) x (speed)
Momentum = (2400 kg) x (20 m/s)
Momentum = 48,000 km-m/s
To completely stop the car, the impulse = -48,000 km-m/s .
 
        
             
        
        
        
Gravity.: Gravity is the force that acts at a right angle to the path of an orbiting object.