 # a staircase contains three steps each 10 cm high and 20 cm wide.what should be the minimum horizontal velocity of a ball rolling off the uppermost plane so as to hit directly the lowest plane

11 years ago

The speed should be 10root6. First see max height is 30 cm.now use s=half*g*t(square)

Now divide the distance 60 cm(horizontal range ) by time you get.

The concept is that for max height no initial velocity so get time and for horizontal motion speed is uniform so divide by time to get speed

7 years ago
It is wrong................................?....................................................................
5 years ago
Let A be the point of origin .Then,
Coordinate of x= 40 and coordinate of y =-20
And angle =0°
Thus using equation for path of trajectory we get ,
Y= tan θ x- gx /2(ucos
5 years ago

Let A be the point of origin .Then,
Coordinate of x= 40 and coordinate of y =-20
And angle =0°
Thus using equation for path of trajectory we get ,
Y= tan θ x- gx /2(ucos theta)2
-20= -1000(40)2/2u2
U= 1000(40)
U=200m/s or 2m/s
Hence the minimum velocity wil be2m/s