Physics
The surface tension and vapour pressure of water at 20∘C is 7.28×10^−2 Nm^−1 and 2.33×10^3Pa, respectively. What is the radius of the smallest spherical water droplet which can form without evaporating at 20^∘C?
12
Nov
The surface tension and vapour pressure of water at 20∘C is 7.28×10^−2 Nm^−1 and 2.33×10^3Pa, respectively. What is the radius of the smallest spherical water droplet which can form without evaporating at 20^∘C? respectively. What is the radius of the smallest spherical water droplet which can form without evaporating at 20^∘C? The surface tension and [...]
Two mercury droplets of radii 0.1 cm and 0.2 cm collapse into one single drop. What amount of energy is released? The surface tension of mercury S=435.5×10^−3Nm^−1
12
Nov
Two mercury droplets of radii 0.1 cm and 0.2 cm collapse into one single drop. What amount of energy is released? The surface tension of mercury S=435.5×10^−3Nm^−1 Two mercury droplets of radii 0.1 cm and 0.2 cm collapse into one single drop. What amount of energy is released? The surface tension of mercury S=435.5×10^−3Nm^−1 November [...]
The sap in trees, which consists mainly of water in summer, rises in a system of capillaries of radius r=2.5×10^−5 m. The surface tension of sap is S=7.28×10^−3 Nm^−1 and the angle of contact is 0^∘. Does surface tension alone account for the supply of water to the top of all tress ?
12
Nov
The sap in trees, which consists mainly of water in summer, rises in a system of capillaries of radius r=2.5×10^−5 m. The surface tension of sap is S=7.28×10^−3 Nm^−1 and the angle of contact is 0^∘. Does surface tension alone account for the supply of water to the top of all tress ? Iceberg floats [...]
A cubical block of density ρ is floating on the surface of water. Out of its height L, fraction x is submerged in water. The vessel is in an elevator accelerating upward with acceleration a . What is the fraction immersed?
12
Nov
A cubical block of density ρ is floating on the surface of water. Out of its height L, fraction x is submerged in water. The vessel is in an elevator accelerating upward with acceleration a . What is the fraction immersed? A cubical block of density ρ is floating on the surface of water. Out [...]
On complete combustion, a liter of petrol gives off heat equivalent to 3×10^7 J. In a test drive a car weighing 1200 kg including the mass of driver, runs 15 km per liter while moving with uniform speed on a straight track. Assuming that friction offered by the road surface and air to be uniform. calculate the force of friction acting on the car during the drive, if the efficiency of the car engine were =0.5.
09
Nov
On complete combustion, a liter of petrol gives off heat equivalent to 3×10^7 J. In a test drive a car weighing 1200 kg including the mass of driver, runs 15 km per liter while moving with uniform speed on a straight track. Assuming that friction offered by the road surface and air to be uniform. [...]
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a liter of petrol gives off heat equivalent to 3×10^7 J. In a test drive a car weighing 1200 kg including the mass of driver ,
On complete combustion ,
one gradual and the other steep meet at A from where two stones are allowed to slide down from rest ,
one on each tracks as shown in figure. Which of the following statements is correct? ,
Two inclined frictionless tracks ,
An adult weighing 600N raises the centre of gravity of his body by 0.25m while taking each step of 1m length in jogging. If he jogs for 6km, calculate the energy utilised by him in jogging assuming that there is no energy loss dur to friction of ground and air. Assuming that the body of the adult is capable of converting 10% of energy intake in the form of food, calculate the energy equivalent of food that would be required to compensate energy utilised for jogging.
09
Nov
An adult weighing 600N raises the centre of gravity of his body by 0.25m while taking each step of 1m length in jogging. If he jogs for 6km, calculate the energy utilised by him in jogging assuming that there is no energy loss dur to friction of ground and air. Assuming that the body of [...]
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An adult weighing 600N raises the centre of gravity of his body by 0.25m while taking each step of 1m length in jogging. If he jogs for 6km ,
one gradual and the other steep meet at A from where two stones are allowed to slide down from rest ,
one on each tracks as shown in figure. Which of the following statements is correct? ,
Two inclined frictionless tracks ,
An engine is attached to a wagon through a shock absorber of length 1.5 m. The system with a total mass of 50,000 kg is moving with a speed of 36 km/h when the brakes are applied to bring it to rest. In the process of the system being brought to rest, the spring of the shock absorber gets compressed by 1.0 m. If 90% of energy of the wagon is lost due to friction, calculate the spring constant.
09
Nov
An engine is attached to a wagon through a shock absorber of length 1.5 m. The system with a total mass of 50,000 kg is moving with a speed of 36 km/h when the brakes are applied to bring it to rest. In the process of the system being brought to rest, the spring of [...]
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000 kg is moving with a speed of 36 km/h when the brakes are applied to bring it to rest. In the process of the system being brought to rest ,
An engine is attached to a wagon through a shock absorber of length 1.5 m. The system with a total mass of 50 ,
calculate the spring constant. ,
the spring of the shock absorber gets compressed by 1.0 m. If 90% of energy of the wagon is lost due to friction ,
Suppose the average mass of raindrops is 3.0×10^−5 kg and their average terminal velocity 9ms^−1. Calculate the energy transferred by rain to each square metre of the surface at the place which receives 100 cm of rain in a year.
09
Nov
Suppose the average mass of raindrops is 3.0×10^−5 kg and their average terminal velocity 9ms^−1. Calculate the energy transferred by rain to each square metre of the surface at the place which receives 100 cm of rain in a year. one gradual and the other steep meet at A from where two stones are allowed [...]
Two pendulums with identical bobs and length are suspended from a common support such that in rest position the two bobs are in contact. One of the bobs is released after being displaced by 10^o so that it collides elastically head on with the other bob. (a) Describe the motion of two bobs. (b) Draw a graph showing variation in energy of either pendulum with time, for 0 ≤ t ≤ 2T, where T is the period of each pendulum.
09
Nov
Two pendulums with identical bobs and length are suspended from a common support such that in rest position the two bobs are in contact. One of the bobs is released after being displaced by 10^o so that it collides elastically head on with the other bob. (a) Describe the motion of two bobs. (b) Draw [...]
A raindrop of mass 1.00 g falling from a height of 1 km hits the ground with a speed of 50 m s^–1. Calculate (a) the loss of P.E. of the drop. (b) the gain in K.E. of the drop. (c) Is the gain in K.E. equal to loss of P.E.? If not why. Take g = 10 m s^2
09
Nov
A raindrop of mass 1.00 g falling from a height of 1 km hits the ground with a speed of 50 m s^–1. Calculate (a) the loss of P.E. of the drop. (b) the gain in K.E. of the drop. (c) Is the gain in K.E. equal to loss of P.E.? If not why. Take [...]