+91-87964 74404
FlagBACK
Question icon
Grade 12th passGeneral Physics

A boy sitting on his horse whips it. The horse speeds up at an average acceleration of 2.0 m/s2 .
  1. If the boy does not slide back, what is the force of friction exerted by the horse on the boy ?
  2. If the boy slides back during acceleration, what can be said about the coefficient of static friction between the horse and the boy.

Profile image of raghav
11 Years agoGrade 12th pass
Answers icon

1 Answer

Profile image of Sumit Majumdar
11 Years ago
Dear student,
The Forces acting on the horse are
(i) the weight Mg
(ii) the normal contact force and
(iii) the static friction f.

(a) As the boy does not slide back, its acceleration a is equal to the acceleration of the horse. As friction is theonly horizontal force, it must act along the acceleration and its magnitude is given by Newton’s second law
f_{s}=Ma=30\times 2=60 N

(b) When the boy slides back, the horse is unable to exert the force of 60 N on the boy. Hence the maximum force that the horse may exert on the boy is:
f_{s}=\mu _{s}mg=\mu _{s}\times 30\times 10=300\mu _{s}
Theerefore300\mu _{s}<60\Rightarrow \mu _{s}<\frac{60}{300}=0.2
Regards
Sumit

Other Related Questions on general physics

question mark

 In viewing through a magnifying glass, one usually positions one's eyes very close to the lens. Does angular magnification change if the eye is moved back?

general physics
1 Answer Available

Last Activity: 9 Months ago

question mark
moment of inertia of a equilateral triangle about an axis passing through centre and perppendicular to the plane
general physics
1 Answer Available

Last Activity: 3 Years ago

question mark
. Because of the rotation of the earth, a plumb bob may not hang exactly along the direction of
the earth’s gravitational pull (its weight) but deviates slightly from this direction. Calculate the
deviation (a) at 40 latitude, (b) at the poles, and (c) at the equator
general physics
1 Answer Available

Last Activity: 3 Years ago

question mark
The length of a massless rod is measured using vernier callipers having 10 vernier scale divisions and least count of 0.1 mm. Two masses 1.00 ± 0.01 kg and 4.00 ± 0.02 kg are attached to its ends. If reading of vernier scale is 5 divisions coinciding with 1.3 cm, what is the % error in locating centre of mass from lighter mass
general physics
2 Answers Available

Last Activity: 3 Years ago

question mark
A block is kept on x-y plane at a point (2m,3m). It is pushed with a force of magnitude 10 Ntowards point (5m,7m). The force can be represented as?
general physics
1 Answer Available

Last Activity: 3 Years ago