Untitled Document

Question Bank No: 2

1. A car accelerates from rest at a constant rate $α$ for some time after which it deccelerates at a constant rate $β$ to rest. If the total time elapsed is t, the maximum velocity acquired by the car is given by

a)		$[\frac{α^{2} + β^{2}}{α β}] t$
b)		$[\frac{α^{2} - β^{2}}{α β}] t$
c)		$[\frac{α + β}{α β}] t$
d)		$[\frac{α β}{α + β}] t$

2. A car starts from rest and moves with constant acceleration. The ratio of the distance covered in the nth second to that covered in n seconds is

a)		$\frac{2}{n^{2}} - \frac{1}{n}$
b)		$\frac{2}{n^{2}} + \frac{1}{n}$
c)		$\frac{2}{n} - \frac{1}{n^{2}}$
d)		$\frac{2}{n} + \frac{1}{n^{2}}$

3. A train of 150 m length is going towards north direction at a speed of 10 m/s. A bird flies at a speed of 5 m/s towards south direction parallel to the railway track. The time taken by the bird to cross the train is equal to

a)		20 sec
b)		16 sec
c)		12 sec
d)		10 sec

4. In a race for 100 m dash, the first and the second runners have a gap of one metre at the mid-way stage. Assuming the first runner goes steady, by whar percentage should the second runner increases his speed just to win the race?

a)		2 $%$
b)		4 $%$
c)		$> 4 %$
d)		< 4 %

5. If for a particle position $x α t^{2}$ , then

a)		velocity is constant
b)		acceleration is constant
c)		acceleration is variable
d)		none of these

6. A body freely falling from the rest has a velocity v after it falls through a heigh h. The distance it has to fall down further for its velocity to become double is

a)		4 h
b)		6 h
c)		8 h
d)		10 h

7. A car with a vertical windshield moves along in a rain strom at speed of 40 km/h. The rain drops fall vertically with a terminal speed of 20m/s. The angle at which the rain drops strike the windshield is

a)		$\tan^{- 1} \frac{2}{3}$
b)		$\tan^{- 1} \frac{5}{9}$
c)		$\tan^{- 1} \frac{3}{2}$
d)		$\tan^{- 1} \frac{9}{5}$

8. The water drops fall at regular intervals from a tap 5 m above the ground. The third drop is leaving the tap at the instant the first drop touches the ground. How far above the ground is the second drop at that instant?

a)		1.25 m
b)		2.50 m
c)		3.75 m
d)		4.00 m

9. A body dropped from a height h with initial velocity zero, strikes the ground with a velocity of 3 m/s. Another body of same mass is dropped from the same height h with an initial velocity of 4 m/s. Find the final velocity of second mass with which it strikes the ground?

a)		3 m/s
b)		4 m/s
c)		5 m/s
d)		12 m/s

10. A ball is thrown upwards from the ground. It is at a height 100m in upward and downward journeys at times $t_{1}$ and $t_{2}$ respectively. If $g = 10 \frac{m}{s^{2}}$ , then $t_{1}$ $t_{2}$ is equal to

a)		10
b)		20
c)		40
d)		50

11. A bus is moving with a velocity 10 m/s on a straight road. A scooterist wishes to overtake the bus in 100 sec. If the bus is at a distance of 1 km from the scooterist, with what velocity should the scooterist chase the bus?

a)		50 m/s
b)		40 m/s
c)		30 m/s
d)		20 m/s

12. In a motion with constant acceleration, the velocity is reduced to zero in 5 seconds and after covering a distance of 100 m. The distance covered by the particle in next 5 seconds will be

a)		zero
b)		250 m
c)		100 m
d)		500 m

13. Which one of the following represents the time- displacement graph of two objects A and B moving the zero relative speed?

a)
b)
c)
d)

14. Which of the following curves do not represent motion in one dimension ?

a)
b)
c)
d)

15. A particle moves along x- axis in such a way that its x- coordinate variws with time t according to the equation $x = (8 - 4 t = 6 t^{2})$ metre. The velocity of the particle will vary with time according to the graph shown the figure.

a)
b)
c)
d)

16. The (acceleration time) graph of a particle moving along a straight line is shown in the figure. At what time the particle acquires its initial velocity?
mod-q5

a)		5 s
b)		12 s
c)		8 s
d)		16 s

17. An athlete completes half a round of a circular track of radius R, then the displacement and distance covered by the athlete are

a)		2R and $π R$
b)		$π R and 2 R$
c)		R and 2 $π R$
d)		2 $π R and R$

18. A particle moving on a strainght line ultimately comes to rest. What is the angle between its initial velocity and acceleration ?

a)		zero
b)		$\frac{π}{4}$
c)		$\frac{π}{2}$
d)		$π$

19. The slope of velocity -time graph for retarded motion is

a)		positive
b)		negative
c)		zero
d)		none of these

20. If a body starts from rest, the time in which it covers a particular displacement with uniform acceleration is

a)		inversely proportional to the square root of the displacement
b)		inversely proportional to the displacement
c)		directly proportional to the displacement
d)		directly proportional to the square root of the displacement