Question

When two forces are combined, the size of the resultant depends on the angle between the two
forces.
Which of the following can not be the magnitude of the resultant when forces of magnitude 3N
and 4 N are combined?
B 3N
A 1N
D 8N
C7N

Answer 1

Answer:

R=√A^2+B^2+2ABcos©

maximum value of cos © is 1 and minimum is -1

so maximum value of resultant

R=√9+16+2×3×4×1

R=√9+16+24=√49=7N

minimum value of resultant

R=√9+16+2×3×4×-1=√9+16-24=√25-24=√1=1 N

so according to the given options,

d) 8N cannot be the magnitude of the resultant force.

so d is the correct answer

Answer 2

Answer: d

Explanation:R=√A^2+B^2+2ABcos©

maximum value of cos © is 1 and minimum is -1

so maximum value of resultant

R=√9+16+2×3×4×1

R=√9+16+24=√49=7N

minimum value of resultant

R=√9+16+2×3×4×-1=√9+16-24=√25-24=√1=1 N

so according to the given options,

d) 8N cannot be the magnitude of the resultant force.

so d is the correct answer