1
NEET 2017
MCQ (Single Correct Answer)
+4
-1
Change Language
Preeti reached the metro station and found that the escalator was not working. She walked up the sationary escalator in time t1. On another days, if she remains stationary on the the moving escalator, then the escalator takes her up in time t2. The time taken by her to walk up on the moving escalator will be
A
$${{{t_1}{t_2}} \over {{t_2} - {t_1}}}$$
B
$${{{t_1}{t_2}} \over {{t_2} + {t_1}}}$$
C
$${{t_1} - {t_2}}$$
D
$${{{t_1} + {t_2}} \over 2}$$
2
NEET 2017
MCQ (Single Correct Answer)
+4
-1
Change Language
One end of string of length $$l$$ is connected to a particle of mass 'm' and the other end is connected to a small peg on a smooth horizontal table. If the particle moves in circle with speed '$$\upsilon $$', the net force on the particle (directed towards centre) will be (T represents the tension in the string)
A
$$T + {{m{v^2}} \over l}$$
B
$$T - {{m{v^2}} \over l}$$
C
zero
D
$$T$$
3
NEET 2017
MCQ (Single Correct Answer)
+4
-1
Change Language
Two blocks A and B of masses 3m and m respectively are connected by a massless and inextensible string. The whole system is suspended by a massless spring as shown in figure. The magnitudes of acceleration of A and B immediately after the string is cut, are respectively

NEET 2017 Physics - Laws of Motion Question 28 English
A
$${g \over 3},g$$
B
$$g, g$$
C
$${g \over 3},{g \over 3}$$
D
$$g,{g \over 3}$$
4
NEET 2017
MCQ (Single Correct Answer)
+4
-1
Change Language
Consider a drop of rain water having mass 1 g falling from a height of 1 km. It hits the ground with a speed of 50 m s$$-$$1. Take 'g' constant with a value 10 m s$$-$$2. The work done by the (i) gravitational force and the (ii) resistive force of air is
A
(i) 1.25 j   (ii) $$-$$8.25 J
B
(i) 100 j   (ii) 8.75 J
C
(i) 10 j   (ii) $$-$$8.75 J
D
(i) $$-$$10 j   (ii) $$-$$8.25 J