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Laws Of Motion

Question
CBSEENPH11020065

A body of mass 5 kg is acted upon by two perpendicular forces 8 N and 6 N. Give the magnitude and direction of the acceleration of the body.

Solution

Mass of the body, m = 5 kg
The given situation can be represented as follows:


The resultant of two forces is given by, 
R = square root of left parenthesis 8 right parenthesis squared plus left parenthesis negative 6 right parenthesis squared end root space equals space square root of 64 space plus space 36 end root space equals space 10 space straight N
straight theta is the angle made by R with the force of 8 N.
Therefore, 
straight theta space equals space tan to the power of negative 1 end exponent space open parentheses negative 6 over 8 close parentheses space equals space minus 36.87 to the power of straight o
The negative sign indicates that θ is in the clockwise direction with respect to the force of magnitude 8 N.
According to Newton’s second law of motion
Acceleration (a) of the body is given as, 
F = ma 
Therefore, 
a =straight F over straight m space equals space 10 over 5 space equals space 2 space m divided by s squared