Page 161 - WCS - Electrical

WORKSHOP CALCULATION & SCIENCE - CITS

4 A man pulls a car of mass 150 kg and produces an acceleration of 4 m/sec . Find the force exerted by man.
2
Solution: mass m = 150 kg Acceleration a = 4 m/sec 2
Force = Mass x Acceleration = m. a
= 150 x 4 = 600 newtons Force exerted by man = 600 newtons Ans.
5 A force of 25 N is applied at the end of a spanner whose effective length is 19.5 cm. Calculate the torque.
Solution: Force applied = 25 Newtons Radius i.e., effective length = 19.5 cm

= 0. 195 metre Torque= Force x Radius
= 25 newtons x 0.195 metres
= 25x 0.195 newton metres
= 4.875 newton metres Torque = 4.875 newton metres Ans.

ASSIGNMENTS
Choose the correct answers:
1 The force acts on a body by which it is attracted by the earth towards its center is known as ……….
a Density b weight
c mass d force
2 After a slight displacement a body does not regain its original position, it is called ………….

a Stable equilibrium b unstable equilibrium
c neutral equilibrium d triangle of free
3 To every action there is always an equal and opposite reaction. This theorem is …………..
a Newton’s second law b Low of conservation of momentum

c newton’s third law d low of conservation of energy
4 Which low states that for every action there is always an equal and opposite reaction?
a Newton’s first law of motion
b Newton’s second law of motion
c Newton’s third law of motion

d Law of conservation of momentum
5 In MKS/SI system which unit is the absolute unit of weight?
a 1 newton b 1 dyne
c 1 poundal d 1 newton/m
6 What is the product of mass of a body and the acceleration due to gravity?

a Force b work
c weight d Energy
7 1 dyne = ………………….
a 1 gm x 1 cm/sec2
b 1 gm x 1 mm/ sec2

c 1 gm x 1 m/ sec 2

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CITS : WCS - Electrical - Exercise 13