### NEET Physics - New - Motion in a Straight line

#### Question - 1

A ball is thrown vertically downward with a velocity of 20m/s from the top of a tower. It hits the ground after some time with a velocity of 80 m/s. The height of the tower is ___________

• A 300m
• B 360m
• C 340m
• D 320m

#### Question - 2

The speed of a swimmer in still water is 20 m/s. The speed of river water is 10 m/s and is flowing due east. If he is standing on the south bank and wishes to cross the river along the shortest path the angle at which he should make his strokes w.r.t. north is given by __________ .

• A 0o
• B 60owest
• C 45owest
• D 30owest

#### Question - 3

Preeti reached the metro station and found that the escalator was not working. She walked up the stationary escalator in time t1. On other days, if she remains stationary on the moving escalator, the escalator takes her up in time t2. The time taken by her to walk up on the moving escalator will be _________

• A $\frac{t_{1}+t_{2}}{2}$
• B $\frac{t_{1} t_{2}}{t_{2}-t_{1}}$
• C $\frac{t_{1} t_{2}}{t_{2}+t_{1}}$
• D $t_{1}-t_{2}$

#### Question - 4

Two cars P and Q start form a point at the same time in a straight line and their positions are represented,by Xp(t) = at + bt2 and Xq(t) = ft - t2 . X wnat time do the cars have the same velocity?

• A $\frac{a-f}{1+b}$
• B $\frac{a+f}{2(b-1)}$
• C $\frac{a+f}{2(1+b)}$
• D $\frac{f-a}{2(1+b)}$

#### Question - 5

A particle of unit mass undergoes one-dimensional motion such that its velocity varies according to v(x) = bx-2n where b and n are constants and x is the position of the particle. The acceleration of the particle as d function of x, is given by ________

• A $-2 n b^{2} x^{-4 n-1}$
• B $-2 b^{2} x^{-2 n+1}$
• C $-2 n b^{2} e^{-4 n+1}$
• D $-2 n b^{2} x^{-2 n-1}$

#### Question - 6

The displacement 'x' (in meter) of a particle of mass 'm' (in kg) moving in one dimensions under the action of a force, is related to time 't (in sec) by t = $\sqrt 3$ + 3 . The displacement of the particle when its velocity is zero, will be ____________.

• A 2m
• B 4m
• C 6m
• D zero

#### Question - 7

A stone falls freely under gravity. It covers distances h1, h2 and h3 in the first 5 seconds, the next 5 seconds and the nxet 5 seconds respectively. The relation between h1, h2 and h3 ____________

• A $h_{1}=\frac{h_{2}}{3}=\frac{h_{3}}{5}$
• B $h_{2}=3 h_{1}\ and\ h_{3}=3 h_{2}$
• C $h_{1}=h_{2}=h_{3}$
• D $h_{1}=2h_{2}=3h_{3}$

#### Question - 8

The motion of a pticle almg a straight line is described by equation x = 8+12t-t3 where x is in metere and t and second. The reterdation of the particle when its velocity becomes zero, is ____________

• A 24ms-1
• B zero
• C 6ms-2
• D 12ms-2

#### Question - 9

A particle covers half of its total distance with speed v1 and the rest half distance with speed v2. Its average speed during the cmplete journey is _______

• A $\frac{v_{1} v_{2}}{v_{1}+v_{2}}\\$
• B $\frac{2 v_{1} v_{2}}{v_{1}+v_{2}}$
• C $\frac{2 v_{1}^{2} v_{2}^{2}}{v_{1}^{2}+v_{2}^{2}}$
• D $\frac{v_{1}+v_{2}}{2}$

#### Question - 10

A body is moving with velocity 30 m/s towards east. After 10 seconds its velocity becomes 40 mis towards north. The average acceleration of the body is __________

• A 1m/s2
• B 7m/s2
• C 7m/s2
• D 5m/s2