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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Which of the choices below is one of the primary gases found in the atmosphere? a. helium b. carbon dioxide c. nitrogen d. argon

Review multiple-concept example 7 in this chapter as an aid in solving this problem. in a fast-pitch softball game the pitcher is impressive to watch, as she delivers a pitch by rapidly whirling her arm around so that the ball in her hand moves in a circle. in one instance, the radius of the circle is 0.626 m. at one point on this circle, the ball has an angular acceleration of 66.1 rad/s2 and an angular speed of 12.6 rad/s. (a) find the magnitude of the total acceleration (centripetal plus tangential) of the ball. (b) determine the angle of the total acceleration relative to the radial direction.

First answer marked as brainiest which is the correct equation describing the first law of thermodynamics? a) when the internal energy of a system changes, it equals the amount of heat added plus the work done. b) when work is done by the piston, it is equal to the heat added plus the change in internal energy of the system. c) when heat is added to the system, it is equal to the amount of work done by the piston plus the change in internal energy of the system.