A 0.5 kg ball is thrown up with an initial speed 14 m/s and reaches a maximum height of 8.0m. How much energy is dissipated by air drag acting on the ball during the ascent
(1) 19.6 Joule
(2) 4.9 Joule
(3) 10 Joule
(4) 9.8 Joule
An ice cream has a marked value of 700 kcal. How many kilowatt- hour of energy will it deliver to the body as it is digested
(1) 0.81 kWh
(2) 0.90 kWh
(3) 1.11 kWh
(4) 0.71 kWh
A particle of mass m at rest is acted upon by a force F for a time t. Its Kinetic energy after an interval t is
(1)
(2)
(3)
(4)
A block of mass m initially at rest, is dropped from a height h onto a spring of force constant k. If the maximum compression in the spring is x, then:
1.
2.
3.
4.
A block of mass \(M\) moving on the frictionless horizontal surface collides with the spring of spring constant \(k\) and compresses it by length \(L.\) The maximum momentum of the block after the collision will be:
1. | zero | 2. | \(ML^2 \over k\) |
3. | \(\sqrt{Mk}L\) | 4. | \(kL^2 \over 2M\) |
A 60 kg man runs up a staircase in 12 seconds while a 50 kg man runs up the same staircase in 11, seconds, the ratio of the rate of doing their work is
(1) 6 : 5
(2) 12 : 11
(3) 11 : 10
(4) 10 : 11
What average horsepower is developed by an 80 kg man while climbing in 10 s a flight of stairs that rises 6 m vertically
(1) 0.63 HP
(2) 1.26 HP
(3) 1.8 HP
(4) 2.1 HP
An engine pump is used to pump a liquid of density ρ continuously through a pipe of cross-sectional area A. If the speed of flow of the liquid in the pipe is v, then the rate at which kinetic energy is being imparted to the liquid is
(1)
(2)
(3)
(4)
A particle free to move along the x-axis has potential energy given by for , where k is a positive constant of appropriate dimensions. Then
(1) At point away from the origin, the particle is in unstable equilibrium
(2) For any finite non-zero value of x, there is a force directed away from the origin
(3) If its total mechanical energy is k/2, it has its minimum kinetic energy at the origin
(4) For small displacements from x = 0, the motion is simple harmonic