A coin is dropped in a lift. It takes time t1 to reach the floor when the lift is stationary. It takes times t2 when the lift is moving up with constant acceleration. Then:
t1 > t2
t2 > t1
t1 = t2
t1 >> t2
A police jeep is chasing with a velocity of 45 km/h, a thief in another jeep moving with velocity 153 km/h. Police fire a bullet with muzzle velocity of 180 m/s. The velocity with which it will strike the car of the thief is :
150 m/s
27 m/s
450 m/s
250 m/s
A car covers 2/5 of a certain distance with speed v1 and rest 3/5 part with velocity v2. The average speed of the car is :
Apparent frequency of sound of engine is changing in the ratio 5/3 under the condition that engine is first aprroaching and then receding away from the observer. If velocity of sound is 340 m/s, then velocity of engine is
340 m/s
170 m/s
85 m/s
310 m/s
If a body travels half the distance with velocity v1 and the next half with velocity v2,its average velocity will be given by
The ratio of the numerical value of the average velocity and average speed of body is always
unity
unity or less
unity or more
less than unity
A wheel of car is revolving at the rate of 1200 cycle/min. On pressing the accelerator, after 10s, it does 4500 cycle/min then radial acceleration of the wheel is
30 rad/s2
1880 degree/s2
40 rad/s2
1980 degree/s2
D.
1980 degree/s2
Given, n1 = 1200 cycle/min = 20 cycle/s
n2 = cycle/s = 75 cycle/s
If a body loses half of its velocity on penetrating 3 cm in a wooden block then how much will it penetrate more before coming to rest?
1 cm
2 cm
3 cm
4 cm
A stone is dropped in 19.6 m depth well, echo is heard in 2.06 s, then velocity of sound is
315.2 m/s
320.5 m/s
326.7 m/s
332.4 m/s
An observer is coming towards plane mirror with a speed of 6 m/s, then apparent velocity of his image is
6 m/s
4 m/s
12 m/s
3 m/s