What should be the tension in a rope pulling vertically upward a mass of 100 kg so that starting from rest it acquires a velocity of 4 m/s in 1.5 seconds?
1278 N
1247 N
1287 N
1894 N
An air craft executes a horizontal loop at a speed of 720 km/h with its wings banked at 15° .What is the radius of the loop?
13 x 103 m
15.2 x 103 m
13.6 x 103 m
None of these
A drum of radius R and mass M ,rolls down without slipping along an inclined plane of angle θ.The frictional force
converts translational energy to rotational energy
dissipates energy as heat
decreases the rotational motion
decreases the rotational and translational motion
A 5000 kg rocket is set for vertical firing.The exhaust speed is 800 m/s and acceleration(a) of the rocket is 20 m/s2.The acceleration due to gravity is 10 m/s2.The amount of gas ejected per second is
127.5 kg/s
137.5 kg/s
185.5 kg/s
187.5 kg/s
The upper half of an inclined plane of inclination θ is perfectly smooth while the lower is rough.A body starting from rest at the top comes back to rest at the bottom,if the coefficient of friction for the lower half is given by
μ = sin θ
μ = cotθ
μ = 2 cosθ
μ = 2 tanθ
A shell is fired from a canon, it explodes in mid air, its total
momentum increases
momentum decreases
kinetic energy increases
kinetic energy decreases
Two trains A and B are running in the same direction on parallel tracks such that A is faster than B.If packets of equal weight are exchanged between the two, then
A will be retarded but B will be accelerated
A will be accelerated but B will be retarded
there will not be any change in the velocity of A but B will be accelerated.
there will not be any change in the velocity of B,but A will be accelerated.
A man slides down a light rope whose breaking strength is η times his weight .What should be his maximum acceleration so that the rope does not break ?
g (1 - η)
ηg
g /1+η
g/1 - η
Two blocks P and Q are released at the top of a rough inclined plane so that P slides along the plane and Q falls down freely. Which will have higher velocity on reaching the ground?
P
Q
Both will reach the ground with same velocity
It depends on the coefficient of friction
A heavy uniform chain lies on horizontal table top.If the coeffecient of friction between the chain and the table surface is 0.25,then the maximum friction of the length of the chain that can hang over one edge of the table is
20 %
25 %
35 %
15 %
