When a boat enters the sea from a river, then?
(A) rises slightly upwards
(B) sinks slightly
(C) remains unchanged
(D) none of these
The correct answer is It rises a little. A ship rises a little when enters the sea from a river. Because of salinity, seawater has more density than river water. In the sea, the more buoyant force is exerted upon the ship than in the river.
What is Newton's first law of motion called?
(A) Law of conservation of momentum
(B) Law of mobility
(C) Law of inertia
(D) None of these
If the velocity of an object is doubled?
(A) momentum is doubled
(B) kinetic energy becomes four times
(C) both of the above
(D) none of these
When the speed of a moving object is doubled, then its kinetic energy?
(A) doubles
(B) increases three times
(C) remains the same
(D) quadruples
The change in the kinetic energy of the object as the speed changes is proportional to the square of the factor by which the speed changes. If the speed of the object becomes double, its kinetic energy changes to four times the initial kinetic energy.
If a cyclist goes round a turn, then he
(A) bends outward
(B) bends inwards
(C) leans forward
(D) does not bend at all
A cyclist bends inwards at a turn to balance the centrifugal force with the centripetal force. If the cyclist does not bend on the curve of the road the force will propel him outward of the road and would make him crash.
Cyclotron is used to accelerate what?
(A) Nuclear
(B) Ion
(C) Proton
(D) All of these
When a ship moving in a river reaches the sea, then the level of the ship?
(A) same as before
(B) will come down slightly
(C) will come up slightly
(D) none of these
When water is filled in a bottle and it is allowed to freeze, the bottle breaks because?
(A) the bottle shrinks at freezing point
(B) water expands on heating
(C) the temperature outside the bottle is higher than inside
(D) water expands on freezing
If we move from the equator towards the poles, then the value of g?
(A) increases
(B) remains the same
(C) decreases
(D) none of these
Force is the product of?
(A) mass and velocity
(B) weight and acceleration
(C) mass and acceleration
(D) weight and velocity
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