A body falls freely for 10 s. Its average velocity during this journey is (Take, g = 10 ms-2)
100 ms-1
10 ms-1
50 ms-1
5 ms-1
C.
50 ms-1
In 10 s, the distance covered by the body
The velocity-time graph for two bodies A and B are shown in figure. Then, the acceleration of Aand B are in the ratio
sin 25° to sin 50°
tan 25° to tan 40°
cos 25° to cos 50°
tan 25° to tan 50°
D.
tan 25° to tan 50°
Acceleration deals with a change in speed magnitude, a change in direction or change in both.
Acceleration represents the slope of velocity-time graph
From the top of a tower a stone is thrown up which reaches the ground in a time t1. A second stone thrown down with the same speed reaches the ground in a time t2. A third stone released from rest from the same between reaches the ground in a time t3. Then
D.
When stone is thrown up
When thrown down,
When released
Two identical charged spheres suspended from a common point by two massless strings of lengths l, are initially at a distance d (d < l) apart because of their mutual repulsion. The charges begin to leak from both the spheres at a constant rate. As a result, the spheres approach each other with a velocity v. Then, v varies as a function of the distance x between the sphere, as
vx
vx-1
B.
Two identical charged spheres suspended from a common point by two massless strings of length L.
In △ABC,
The charge begins to leak from both the sphere at a constant rate. As a result, the spheres approach each other with velocity v.
Therefore, equation (i) can be rewritten as,