# Kinematics of a particle moving

• November 25th 2009, 06:25 PM
Sashikala
Kinematics of a particle moving
Could you please help me on the part (c) and (d) of the problem given
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.

• November 26th 2009, 06:59 AM
skeeter
Quote:

Originally Posted by Sashikala
Could you please help me on the part (c) and (d) of the problem given
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) $F_{net} = ma = f_k = \mu mg$

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

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

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

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

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

sum the two times.
• November 27th 2009, 08:06 AM
Sashikala
Thanks a lot Skeeter.