Answer:
A×B=C×D
500×0.5=250×X
250=250×X
X=250/250=1
X=1 m
Explanation:
note: if the force plus two, the distance will be half.
 
        
             
        
        
        
Answer: 
A) 0.660 g/ml
B) 1.297 ml
C) 0.272 g
Explanation:
Every substance, body or material has mass and volume, however the mass of different substances occupy different volumes.  This is where density 
 appears as a  physical characteristic property of matter that establishes a relationship between the mass 
 of a body or substance and the volume 
 it occupies:
 (1)
Knowing this, let's begin with the answers:
<h2 /><h2>Answer A:</h2>
Here the mass is 
 and th volume 
 
Solving (1) with these values:
 (2)
 (3)
<h2>Answer B:</h2>
In this case the mass of a sample is 
 and its density is 
. 
Isolating 
 from (1):
 (4)
 (5)
 (5)
<h2>Answer C:</h2>
In this case the volume of a sample is 
 and its density is 
. 
Isolating 
 from (1):
 (6)
 (7)
 (8)
 
        
                    
             
        
        
        
Answer:
false statement : b )  For the motion of a cart on an incline plane having a coefficient of kinetic friction of 0.5, the magnitude of the change in kinetic energy equals the magnitude of the change in gravitational potential energy
Explanation:
mechanical energy = potential energy + kinetic energy = constant 
differentiating both side 
Δ potential energy + Δ kinetic energy = 0 
Δ potential energy = -  Δ kinetic energy
first statement is true. 
Friction is a non conservative force so inter-conversion of potential and kinetic energy is not possible in that case. In case of second  option,  the correct relation is as follows 
change in gravitational potential energy = change in kinetic energy + work done against friction . 
So given 2 nd  option is incorrect. 
In case of no change in gravitational energy , work done is equal to 
change in kinetic energy. 
 
        
             
        
        
        
The answer is A
Explanation: 
Vacuuming doesn’t involve a lot of physical movements.