A stone was thrown vertically upwards from the ground with a velocity of 50 m/sec. After 5 seconds another stone was thrown vertically upwards from the same place. If both the stones strike the ground at the same time, then the velocity with which the second stone was thrown should be (Assume g = 10 m/sec²)
15 m/sec
25 m/sec
40 m/sec
50 m/sec
Correct Answer :
B. 25 m/sec
Related Questions
The resultant of two forces acting at right angles is √34 kg and acting at 60° is 70 kg. The forces are
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2 kg and 3 kg
√3 kg and √5 kg
3 kg and 5 kg
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Everybody continues in its state of rest or of uniform motion in a straight line, unless it is acted upon by some external force
The rate of change of momentum is directly proportional to the impressed force, and takes place in the same direction, in which the force acts
To every action, there is always an equal and opposite reaction
All the above
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Be in equilibrium
Always reduce to a resultant force
Always reduce to a couple
Both (A) and (C)
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Algebraic sum of forces, constituting a couple is zero
Algebraic sum of moments of forces, constituting a couple, about any point, is same
A couple can be never the balanced by a single force
All the above
Two objects moving with uniform speeds are 5 m apart after 1 second when they move towards each other and are 1 m apart when they move in the same direction. The speeds of the objects are
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3 m/sec and 3 m/sec
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A spring scale in a stationary lift shows a reading of 60 kg for a man standing on it. If the lift starts descending at an acceleration of g/5, the scale reading would be
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r
r²
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1.0 m/sec
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A shell of mass 100 kg travelling with a velocity of 10 m/sec breaks into two equal pieces during an explosion which provides an extra kinetic energy of 20000 Joules. If the pieces continue to move in the same direction as before, then the speed of the faster one must be
20 m/sec
30 m/sec
40 m/sec
50 m/sec
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490 m
980 m
1960 m
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sin θ
cos θ
tan θ
cosec θ
One Newton force, is
103 dynes
104 dynes
105 dynes
106 dynes
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Zero
Maximum
Minimum
Varying
The equation of motion of a particle starting from rest along a straight line is x = t3 - 3l2 + 5. The ratio of the velocities after 5 sec and 3 sec will be
2
3
4
5
M.I. of solid sphere, is
Mr2
½ Mr2
Mr2
πr4/2
A funicular polygon cannot be made to pass through
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Two specified points
Three specified points
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150 J
200 J
400 J
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Velocity is maximum at its mean position
Velocity is minimum at the end of the stroke
Acceleration is minimum at the end of the stroke
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Three forces acting at a point, can be rep-resented by the sides of a triangle, each side being in proportion to the force
Three forces acting along the sides of a triangle are always in equilibrium
If three forces acting on a, point can be represented in magnitude and direction, by the sides of a triangle taken in order, these will be in equilibrium
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15°
30°
45°
75°
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30°
45°
90°
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2 m × 3 m
1 m × 3 m
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1 radian/sec
100 radian/sec
1000 radian/sec
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Zero
2 t
3 t
1 t
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AB
BC
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A ball moving with a velocity of 5 m/sec impinges a fixed plane at an angle of 45° and its direction after impact is equally inclined to the line of impact. If the coefficient of restitution is 0.5, the velocity of the ball after impact will be
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1.5 m/sec
2.5 m/sec
3.5 m/sec
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A load of 500 kg was lifted through a distance of 13 cm. by an effort of 25 kg which moved through a distance of 650 cm. The mechanical advantage of the lifting machine is
15
18
20
26