A Particle has initial velocity and has acceleration. Its speed after 10s is
7 unit
8.5 unit
8.5 unit
B.
unitSix vectors and have the magnitudes and directions indicated in the figure. Which of the following statements is true?
C.
If two non -zero vectors are represented by the two adjacent sides of a parallelogram, then the resultant is given by the diagonal of the parallelogram passing through the point of intersection of the two vectors
therefore,
A particle moves a distance x in time t according to equation x = (t +5)-1. The acceleration of particle is proportional to
(velocity)3/2
(distance)2
(distance)-2
(distance)-2
A.
(velocity)3/2
Given, distance x = ( t + 5)-1 ...... (i)
Differentiating eq. (i) w.r.t, we get
The speed of the projectile at its maximum height is half of its initial speed. The angle of projection is
60o
15o
30o
30o
A.
60o
The speed of projectile at its maximum height
v' = vo cos θ
vo/2 = vo cos θ
cos θ = 1/2
θ = 60o
Two particles which are initially at rest, move towards each other under the action of their internal attraction. If their speeds are v and 2v at any instant, then the speed of centre of mass of the system will be
2v
0
1.5 v
1.5 v
B.
0
As initially, both the particles were at rest, therefore, velocity of the centre of mass was zero and there is no external force on the system so the speed of the centre of mass remains constant i.e, it should be equal to zero.