Answer: 6.9x 107 in standard form is 69,000,000
Answer: coefficient of static friction
= 0.31
Explanation: Since they negotiate the curve without skidding, the frictional force (F1) equals the centripetal force (F2).
F1= uN
F2 = M*(v²/r)
M is the combined mass 450kg
V is the velocity 18m/s
r is the radius 106m
N is the normal reaction 4410N
u is the coefficient of static friction
Making u subject of the formula we have that,
u = {450*(18²/106)} /4410
=1375.47/4410
=0.31
NOTE: coefficient of friction is dimensionless. It as no Unit.
Answer: The correct answer is Image B.
Explanation: For an object to accelerate, there should be unbalanced forces present. An object will move in the direction of net force.
Balanced forces are defined as the forces acting on the same object which are equal in magnitude but act in opposite direction. The net forces are 0.
Unbalanced forces are defined as the forces acting on the same object which are unequal in magnitude. The net force is non-zero.
For the given images:
Image A: This box will accelerate easily because the net force is non-zero and is moving in right direction.
Image B: This box will not accelerate because the net force is zero as all the forces are balancing one another. Hence, the object will stay at rest.
Image C: This box will accelerate easily because the net force is non-zero and is acting in between the normal and applied force.
Image D: This box will accelerate easily because the net force is non-zero and is moving in right direction.
Hence, the correct option is Image B.
