In a physics lab experiment, a spring clamped to the table shoots a 18g ball horizontally. When the spring is compressed 22cm , the ball travels horizontally 4.9m and lands on the floor 1.5m below the point at which it left the spring. What is the spring constant?

Question

anonymous · Answer

does its velocity becomes zero after 4.9 m?

anonymous · Answer

frm mgh=1/2mv^2 .. find velocity... then acc. ... then f=ma=kx

anonymous · Answer

okay, found velocity to be 5.42 m/s

anonymous · Answer

how to find acceleration?

souvik · Answer

|dw:1374460539806:dw|
the total mechanical energy is conserved...
so $$mgh+1/2kx^2=1/2mv^2$$...............(1)
where $v$ is velocity when the ball hits the ground...
now the initial horizontal velocity of the ball is zero
so $h=1/2gt^2$
or $t=\sqrt{2h/g}$......[ t= the time taken to fall]

and $v _{y}=g t$
and $v _{x}=4.9/t$
now find v ...using..$$v=\sqrt{v _{x}^{2}+v _{y}^{2}}$$
now put all the data you know in equation 1 and find the spring constant k....