I ) Give one word for the following :- 1. The net force which causes some effect on an object-

2. A device in which ball bearings are used to reduce friction-

II ) Select the correct option :-

1. Buring of a meteor in the atmosphere is due to .
a) Frictional force
b) Magnetic force
c) gravitational force

2. The deep groves in the tyres of a tracter-
a) increase friction
b) decrease friction
c) make it stable

3. The force which an object exerts on any other object is .
a) gravitational force
b) magnetic force
c) electrostatic force
d) frictional force

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The 10-kg double wheel with radius of gyration of 125mm about o is connected to the spring of stiffness k = 600 n/m by a cord which is wrapped securely around the inner hub. if the wheel is released from rest on the incline with the spring stretched 225 mm, calculate the maximum velocity v of its center o during the ensuing motion. the wheel rolls without slipping

Which statements describe the movement of ocean currents around the globe? check all that apply. strong winds force warm water to sink to the ocean floor. the coriolis effect causes warm and cold water to mix. cool dense water sinks to the ocean floor. warm water replaces cool surface water. wind blowing parallel to the shore causes upwelling of cool water.

Boxing gloves are padded to lessen the force of a blow. (a) calculate the force exerted by a boxing glove on an opponent’s face, if the glove and face compress 7.50 cm during a blow in which the 7.00-kg arm and glove are brought to rest from an initial speed of 10.0 m/s. (b) calculate the force exerted by an identical blow in the gory old days when no gloves were used and the knuckles and face would compress only 2.00 cm. (c) discuss the magnitude of the force with glove on. does it seem high enough to cause damage even though it is lower than the force with no glove?