# Class 4 Mechanics

15 Questions | Total Attempts: 41

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• 1.
If two forces F1 = 120 N and F2=80 N are acting at a point making an angle of 55°between them. Find the resultant of these forces in magnitude.
• A.

179.361 N

• B.

177.361 N

• C.

178.361 N

• D.

175.361 N

• 2.
A body weighing 200 N is resting on a horizontal surface. It is just on the point of moving when a horizontal force of 50 N is applied on it. Find coefficient of friction.
• A.

0.35

• B.

0.25

• C.

0.245

• D.

0.24

• 3.
A body weighing 280 N is at a height 10 m above ground level and moving with a velocity 1.6 m/s. Calculate total energy ( in Joules) possessed by the body.
• A.

2834.53

• B.

2838.53

• C.

2840.53

• D.

2836.53

• 4.
Find power of a pump to fill water tank 3m x 2m x 1.5m in 45 minutes. The water is to be lifted through 12 m height. Assume efficiency of pump= 85%
• A.

463.647 W

• B.

464.647 W

• C.

461.647 W

• D.

465.647 W

• 5.
The power of the machine is 10kW. Find the time taken ( in seconds) to lift a body of mass 1000kg to a height of 20m.
• A.

20.62

• B.

18.62

• C.

18.11

• D.

19.62

• 6.
A sail boat weighs 8000 N including occupants. The wind exerts a force of 350 N on the boat. The resistance to motion in water is 200 N. Find the acceleration ( in m/s2) of the boat. Take g= 9.81 m/s2
• A.

0.1439

• B.

0.1639

• C.

0.1839

• D.

0.1939

• 7.
A sphere of mass 0.8 kg has a velocity of 1 m/s. It strikes another sphere of mass 0.7 kg which is at rest. The impact is direct central. If the first sphere comes to rest after impact, find velocity ( in m/s)of the second sphere.
• A.

1.043

• B.

1.343

• C.

1.243

• D.

1.143

• 8.
A flywheel starting from rest under uniform acceleration completes one revolution in 8th second. Find angular acceleration after 15 seconds from start.
• A.

0.1333

• B.

0.1423

• C.

0.1123

• D.

0.1313

• 9.
A man weighing 600 N climbs a staircase of 12 m height in 30 seconds. How much power was consumed?
• A.

0.26 kW

• B.

0.20 kW

• C.

0.24 kW

• D.

0.22 kW

• 10.
A pull of 60 N at 25° up the horizontal is required to just move a block of weight(W). Calculate the weight of the block if µ = 0.25
• A.

244.871 N

• B.

240.871 N

• C.

246.871 N

• D.

242.871 N

• 11.
A vehicle is moving with a velocity of 36 km/hr. If weight of the vehicle is 6 kN, find its kinetic energy.
• A.

30581 J

• B.

30591 J

• C.

30571 J

• D.

30751 J

• 12.
A scooter has an initial velocity of 4 m/s. It accelerates for 12 seconds at the rate of 0.25 m/s2. Determine the final velocity after 12 seconds
• A.

7.2m/s

• B.

6.8 m/s

• C.

7.0 m/s

• D.

7.3 m/s

• 13.
A 40 kN block on 24° inclined plane requires a force of 22 kN to move it up the plane. If the applied force is in the direction of plane, find coefficient of friction between the block and plane.
• A.

0.1368

• B.

0.1468

• C.

0.1568

• D.

0.1668

• 14.
A bowler throws a ball with a speed of 20 m/s. The moment the ball touches the ground, it looses its energy by 12 Joule. Calculate the speed (m/s) at which it hits the bat. Neglect air and other resistances. Mass of the ball is 200 gms.
• A.

15.733

• B.

14.733

• C.

16.733

• D.

17.733

• 15.
A sphere of mass 0.8 kg has a velocity of 1 m/s. It strikes another sphere of mass 0.7 kg which is at rest. The impact is direct central. If the first sphere comes to rest after impact, find velocity ( in m/s)of the second sphere.
• A.

1.103

• B.

1.163

• C.

1.123

• D.

1.143