A substance made of two or more elements is called a what

murzikaleks [220]

Heck yeah i'll follow!!!!!!

4 0

3 years ago

A merter stick pivoted at its center has a 150gm mass suspended at its 20cm mark. a) Where should an 100gm mass be placed to pro

IgorLugansk [536]

Answer:1) 100 gm mass should be placed at 95 cm mark.

2) Mass of 112.5 gm should be placed at 90 cm mark.

Explanation:

For equilibrium of the meter stick the sum of the moment's generated by the masses should be equal and opposite

Answer to part b)

Since a meter stick is 100 cm long and it is pivoted at it's center i.e at 50 cm

Thus

1) Moment generated by 100 gm mass about center = $M_{1}=m_{1}g\times r_{1}\\\\M_{1}=0.15\times 9.81\times 0.3=0.44145Nm$

Let a mass 'm' be placed at 90 cm mark thus moment it generates equals

$M_{2}=m\times 9.81\times 0.4=3.924m$

Equating both the moments we get

$0.44145=3.924m\\\\\therefore m=\frac{0.44145}{3.924}\times 1000grams\\\\\therefore m= 112.5grams$

Answer to part a)

Let the 100 grams weight be placed at a distance 'x' right of center

Moment generated by 100 grams weight equals

$M_{1}=0.1\times 9.81\times x$

equating the moments of the forces we get

$0.1\times 9.81\times x=0.15\times 0.3\times 9.81$

$\therefore x=\frac{0.4415}{.981}=45centimeters$

thus the mass of 100 gm should be placed at 95 cm mark in the scale.

8 0

4 years ago

If a ball of mass, M, moving at velocity, v, collided with a ball of mass 10M at rest, describe what could happen to the velocit

KatRina [158]

Refer to the diagram shown below.

Before collision, the momentum of the two masses is
P₁ = Mv + (10M)*0 = Mv

After the collision, assume that the lighter ball rebounds off the heavier ball with a coefficient of restitution of r, so that v₂ = rv.
If r = 1, the rebound is elastic and v₂ = -v.
If r < 1, the rebound velocity is v₂ = -rv.
If r= 0, the lighter ball sticks to the heavier ball.

The momentum after collision is
P₂ = -Mv₂ + 10Mv₁

Because momentum is conserved, P₁ = P₂. That is,
10Mv₁ - M(rv) = Mv
v₁ = v(1+r)/10 for r>0.

When r=1 (elastic rebound)
v₁ = v/5.
The heavier ball moves right at 20% of the velocity of the lighter ball,
and the lighter ball rebounds with its velocity in the opposite direction.

When 0 < r < 1,
v₁ = (1+r)/10.
The heavier ball travels with greater than 20% of the velocity of the lighter ball, and the lighter ball rebounds with a velocity less than its initial velocity.

When r=0, the balls will stick together and
(10M + M)v₁ = Mv
v₁ = v/11.
The stuck balls move together at 1/11 of the initial velocity of the lighter ball.