# Thread: Kinematics of a particle moving

1. ## Kinematics of a particle moving

below.

A particle of mass 0.5kg is at rest on a horizontal table. It receives a blow of impulse 2.5Ns.

(a) Calculate the speed with which P is moving immediately after the blow

The height of the table is 0.9m and the floor is horizontal. In an initial model of the situation the table is assumed to be smooth.
(b) Calculate the horizontal distance from the egde of the table to the point where P hits the ground.

In a refinement of the model the table is assumed rough. The coefficient of friction between the table and P is 0.2.
(c) Calculate the deacceleration of P.

Given that P travels 0.4m to the edge of the table,
(d) calculate the time which elapses between P receiving the blow to P hitting the floor.

2. Originally Posted by Sashikala
below.

A particle of mass 0.5kg is at rest on a horizontal table. It receives a blow of impulse 2.5Ns.

(a) Calculate the speed with which P is moving immediately after the blow

The height of the table is 0.9m and the floor is horizontal. In an initial model of the situation the table is assumed to be smooth.
(b) Calculate the horizontal distance from the egde of the table to the point where P hits the ground.

In a refinement of the model the table is assumed rough. The coefficient of friction between the table and P is 0.2.
(c) Calculate the deacceleration of P.

Given that P travels 0.4m to the edge of the table,
(d) calculate the time which elapses between P receiving the blow to P hitting the floor.

(c) $\displaystyle F_{net} = ma = f_k = \mu mg$

magnitude of the acceleration is $\displaystyle a = \mu g$

(d) for the time the P slides on the ruff table ...

$\displaystyle \Delta x = v_0 t - \frac{1}{2}at^2$ , solve for $\displaystyle t$

for the time it takes for P to fall to the floor ...

$\displaystyle \Delta y = -\frac{1}{2}gt^2$ , solve for $\displaystyle t$

sum the two times.

3. Thanks a lot Skeeter.