A particle located at x = 0 at time t = 0, starts moving along the positive x-direction with a velocity ‘v’ that varies as v= α√x . The displacement of the particle varies with time as
t3
t2
t
t
A projectile can have the same range R for two angles of projection. If t1 and t2 be the times of flights in the two cases, then the product of the two time of flights is proportional to
R2
1/R2
1/R
1/R
The relation between time t and distance x is t=ax2 +bx where a and b are constants. The acceleration is
−2abv2
2bv3
−2av3
2av2
A car starting from rest accelerates at the rate f through a distance S, then continues at constant speed for time t and then decelerates at the rate f/2 to come to rest. If the total distance traversed is 15 S, then
S=ft
S= ft2/72
S = 1/2 ft2
S = 1/2 ft2
A particle is moving eastwards with a velocity of 5 m/s in 10 seconds the velocity changes to 5 m/s northwards. The average acceleration in this time is
zero
zero
A parachutist after bailing outfalls 50 m without friction. When a parachute opens, it decelerates at 2 m/s2. He reaches the ground with a speed of 3 m/s. At what height, did he bail out?
91 m
182 m
293 m
293 m
A projectile can have the same range R for two angles of projection. If T1 and T2 be the time of flights in the two cases, then the product of the two time of flights is directly proportional to
1/R2
1/R
R
R
Which of the following statements is false for a particle moving in a circle with a constant angular speed?
The velocity vector is tangent to the circle.
The acceleration vector is tangent to the circle.
The acceleration vector points to the centre of the circle.
The acceleration vector points to the centre of the circle.
A body of mass m accelerates uniformly from rest to v1 in time t1. The instantaneous power delivered to the body as a function of time t is
B.
Let the constant acceleration of body of mass m is a.
From equation of motion
v1 = 0 + at1
⇒ a = t2/t1 = ...... (i)
At an instant t, the velocity v of the body v = 0 + at