Advertisements
Advertisements
प्रश्न
A metre scale is moving with uniform velocity. This implies ______.
विकल्प
the force acting on the scale is zero, but a torque about the centre of mass can act on the scale.
the force acting on the scale is zero and the torque acting about centre of mass of the scale is also zero.
the total force acting on it need not be zero but the torque on it is zero.
neither the force nor the torque need to be zero.
Advertisements
उत्तर
A metre scale is moving with uniform velocity. This implies the force acting on the scale is zero and the torque acting about centre of mass of the scale is also zero.
Explanation:
Since the body is moving with a uniform velocity, hence its acceleration is zero. This implies that the net force acting on it must be zero, which further makes the torque acting about the centre of mass of the scale also zero.
APPEARS IN
संबंधित प्रश्न
An aircraft executes a horizontal loop at a speed of 720 km/h with its wings banked at 15°. What is the radius of the loop?
A spy jumps from an airplane with his parachute. The spy accelerates downward for some time when the parachute opens. The acceleration is suddenly checked and the spy slowly falls to the ground. Explain the action of the parachute in checking the acceleration.
Two blocks A and B of mass mA and mB , respectively, are kept in contact on a frictionless table. The experimenter pushes block A from behind, so that the blocks accelerate. If block A exerts force F on block B, what is the force exerted by the experimenter on block A?
An empty plastic box of mass m is found to accelerate up at the rate of g/6 when placed deep inside water. How much sand should be put inside the box so that it may accelerate down at the rate of g/6?
In the following figure, m1 = 5 kg, m2 = 2 kg and F = 1 N. Find the acceleration of either block. Describe the motion of m1 if the string breaks but F continues to act.
State the Newton's second law of motion. What information do you get from it?
Write the mathematical form of Newton's second law of motion. State the conditions if any.
Use Newton's second law of motion to explain the following instance :
A cricketer pulls his hands back while catching a fast moving cricket ball .
The unit of linear momentum is :
The linear momentum of a body of mass m moving with velocity v is :
A force of 10 N acts on a body of mass 2 kg for 3 s, initially at rest. Calculate : The velocity acquired by the body
A stone is dropped from a cliff 98 m high.
What will be its speed when it strikes the ground?
A stone is thrown vertically upward with a velocity of 9.8 m/s. When will it reach the ground?
A ball is thrown upward and reaches a maximum height of 19.6 m. Find its initial speed?
A stone is dropped from a tower 98 m high. With what speed should a second stone be thrown 1 s later so that both hit the ground at the same time?
What do you mean by the conservation of momentum? Briefly, explain the collision between two bodies and the conservation of momentum.
In the previous problem (5.3), the magnitude of the momentum transferred during the hit is ______.
The motion of a particle of mass m is given by x = 0 for t < 0 s, x(t) = A sin 4 pt for 0 < t < (1/4) s (A > o), and x = 0 for t > (1/4) s. Which of the following statements is true?
- The force at t = (1/8) s on the particle is – 16π2 Am.
- The particle is acted upon by on impulse of magnitude 4π2 A m at t = 0 s and t = (1/4) s.
- The particle is not acted upon by any force.
- The particle is not acted upon by a constant force.
- There is no impulse acting on the particle.
What happens when a car brakes to come to a stop?
How does moving your hand backward while catching a cricket ball reduce pain?
