Velocity of sound in vacuum is ____________________?

A. 332 ms-1
B. 320 ms-1
C. Zero
D. 224 ms-1

The velocity of sound is greatest in___________________?

A. Water
B. Air
C. Copper
D. Ammonia

The velocity of sound in air would become double than its velocity at 0°C at temperature ?

A. 313°c
B. 586°c
C. 819°c
D. 1172°c

Ultrasonic have__________________?

A. Frequency in the audible range
B. Frequency is greater than 20 khz
C. Frequency lower than 20 hz
D. All of above

The thrust on the rocket in the absence of gravitational force of attraction is__________________?

A. Constant
B. Not constant
C. Constant if the rate of ejected gases is constant
D. Constant for short range rocket.

When two bodies move toward each other with constant speeds the distance between them decreases at the rate of 6m / sec. If they move in the same direction the distance between them increases at the rate of 4m/sec. Then their speeds are________________?

A. 5m/s, 1m/s
B. 3m/s, 3m/s
C. 6m/s, 1m/s
D. 4m/s, 2m/s

The distance covered by a body in time t starting from rest is__________________?

A. At2/2
B. Vt
C. A2t/2
D. At2

The trajectory (or path) of a projectile is_________________?

A. Straight line
B. Parabola
C. Hyperbola
D. Circle

The force beared by a wall on which water strikes normally at a speed of 10m/sec and at a discharge of 0.0001m3/sec is__________________?

A. 1 n
B. 10 n
C. 100 n
D. None

The range of the projectile at 30 deg and 60 deg are__________________?

A. Equal to 45 deg
B. Equal to 90 deg
C. Equal to each other
D. None of the above