Physics

According to Bernoulli's principle, in a streamline flow, an increase in fluid velocity corresponds to a decrease in pressure. Therefore, the velocity of a fluid increases where the pressure is low.

When a body is whirled in a horizontal circle by a string, the tension in the string provides the inward (centripetal) force necessary to keep the body moving in a circular path. Neither mass, velocity, nor acceleration themselves supply the force; they influence the magnitude of the required centripetal force.

In vertical circular motion, the tension in the string varies with the position of the stone. At the lowest point, the tension is greatest because it must provide the centripetal force to keep the stone moving in a circle and also counteract the weight of the stone (gravity). The tension at the lowest point is given by T = (mv^2)/r + mg, where m is the mass, v is the speed, r is the radius, and g is the acceleration due to gravity. At the highest point, the tension is least and given by T = (mv^2)/r - mg, since gravity assists the centripetal force there. Therefore, the string is most likely to break at the lowest point where the tension is maximum.

The gravitational constant G has units derived from Newton's law of gravitation: F = G * (m1*m2)/r^2. Rearranging, G = F * r^2 / (m1*m2). Since force (F) is in Newtons (N), distance (r) in meters (m), and mass (m) in kilograms (kg), the units of G are N·m²/kg².

One radian is defined as the angle subtended at the center of a circle by an arc whose length is equal to the radius of the circle. This angle is approximately 57.3 degrees, making option B correct.

A body has constant velocity only when it moves in a straight line with constant speed, which corresponds to a rectilinear path. Paths like elliptical, circular, or parabolic involve changes in direction or speed, so velocity is not constant.

The Earth completes one full rotation (2π radians) in approximately 24 hours (86400 seconds). The angular speed ω = 2π / 86400 ≈ 7.27 x 10^-5 radians/second, which matches option D.

The outward force acting on a mass rotating in a circle (often called the centrifugal force in a rotating frame) is equal in magnitude to the centripetal force required to keep it moving in a circle. The centripetal force is calculated by the formula F = m*v^2/r. For a mass of 10 kg, radius 10 m, and speed 1 m/s, the force is F = 10*(1^2)/10 = 1 N. Therefore, the outward force magnitude is also 1 N. Among the given options, 1 N corresponds to option A, making it the correct answer.

A sphygmomanometer measures blood pressure statically by occluding the artery and then slowly releasing pressure to detect systolic and diastolic pressures. It does not measure blood pressure dynamically (continuously over time).

Irregular flow of fluid is known as turbulent flow, characterized by chaotic changes in pressure and flow velocity. Laminar flow, streamline, and uniform flow refer to smooth, orderly fluid motion, which contrasts with turbulent flow.