A bob is hanging over a pulley inside a car through a string.
The second end of the string is in the hand of a person
standing in the car. The car is moving with constant
acceleration a directed horizontally as shown in figure. Other
end of the string is pulled with constant acceleration a
vertically. The tension in the string is equal to-
(a) m sqrt(g^2 + a^2)
(b) m sqrt(g^2 + a^2) -ma
(c) m sqrt(g^2 + a^2) + ma
(d) m (g + a)
the answer is option c. can anyone tell me how to do it? please

Three identical balls are placed on a frictionless horizontal surface touching each other. They stick to each other because of adhesive. Another ball of same radius and mass m is placed over the void created by the three balls. Find the forces applied by the balls kept on the floor to each other if the system remains in equilibrium.

A car loaded with water having total mass 1000 kg moves on a straight horizontal Road starting from rest under the action of a force of 100 Newton. The water spills throw a small hole in the bottom at a rate of 0.1 KG per second the velocity of cart after 300 seconds is nearly.

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