The graphics in the attachment is part of the question, which was incomplete.
Answer: Fr = 102N and angle of approximately 11°.
Explanation: From the attachment, it is observed that from the three forces acting on M, two are perpendicular. So to find them, we have to show their x- and y- axis components. From the graph:
Fx = 70+40-10 = 100
Fy = 40-20 = 20
Now, as the forces form a triangle, the totalforce is:
Fr = 
Fr = 
Fr = ≈ 102N
To determine the angle requested, we use:
arctg H = 
arctg H = 
H = tg 0.2 ≈ 11°.
Answer: C
Explanation:
In endothermic reactions, enthalpy is positive, and in exothermic reactions, enthalpy is negative, So, if enthalpy is positive, then it is an endothermic reaction, and hence is required for the reaction to occur.
Answer: The correct answer is option (A).
Explanation:
Polar molecules are molecules in which formation of partial charges takes place due to which dipole moment gets created in a molecule. Molecules with polar bonds that s bond with partly ionic character. And water is of the example of polar molecule.
Electronegative oxygen atom in water molecule attracts the electron bond pair towards itself which generates partial negative charge on oxygen atom and partial positive charge on both hydrogen atoms.
Where as water has higher value surface tension due to strong intermolecular association of the water molecule due to presence of hydrogen bonding.And it is more denser is liquid state than in its solid state.
Hence,the correct answer is option (A).