SCIENCE TEST 8

GYAN VIKASH BKD

Total Marks : 50

Time Allotted : 1hr 30min

SECTION – A

Q1. . For each question given below four answers are given. Choose the correct answer: 1*5=5

a) Relative Velocity is a -
i) Scaler quantity
ii) Vector quantity
iii) Relative quantity
iv) Fundamental quantity

b) Velocity in a uniform circular motion is called -
i) Circular velocity
ii) Round velocity
iii) Angular velocity
iv) Relative velocity

c) Inertia is directly proportional to -
i) mass
ii) weight
iii) time
iv) all of the above

d) The value of G was found out by -
i) Henry Cavendish
ii) Henry Ford
iii) Issac Newton
iv) Modi Ji

e) The correct formula for g is -

SECTION – B

Q2. Short ans type questions 2*8 = 16

a) What does the speedometer of an automobile measure?

b) Differentiate between uniform motion and non uniform motion?

c) Draw a distance-time graph of an object moving with uniform speed.

d) A racing car has a uniform acceleration of 4 m s-2. What distance will it cover in 10 s after start?

e) Explain why some of the leaves may get detached from a tree if we vigorously shake its branch.

f) A force of 5 N gives a mass m1 , an acceleration of 10 m s–2 and a mass m2 , an acceleration of 20 m s-2 . What acceleration would it give if both the masses were tied together?

g) Define momentum. State the Law of conservation of momentum.

h) Write down the importance of Universal law of gravitation.

SECTION – C

Q3. Answer the following questions 3*9 = 27

a) Derive the three formulae of motion. i.e


b) A bus starting from rest moves with a uniform acceleration of 0.1 m s-2 for 2 minutes. Find (a) the speed acquired, (b) the Q distance travelled.

c) An athlete completes one round of a circular track of diameter 200 m in 40 s. What will be the distance covered and the displacement at the end of 2 minutes 20 s?

d) Explain the laws of motion with a suitable example.

e) Derive F=ma from Newton's second law of motion.

f) The velocity-time graph of a ball of mass 20 g moving along a straight line on a long table is given below

How much force does the table exert on the ball to bring it to rest?

g) Two hockey players of opposite teams, while trying to hit a hockey ball on the ground collide and immediately become entangled. One has a mass of 60 kg and was moving with a velocity 5.0 m s–1 while the other has a mass of 55 kg and was moving faster with a velocity 6.0 m s–1 towards the first player. In which direction and with what velocity will they move after they become entangled? Assume that the frictional force acting between the feet of the two players and ground is negligible.

h) Derive the Gravitational force equation.

i) Differentiate between Mass and Weight.

Q4. Fill in the blanks : 1/2 * 4 = 2

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