A body of mass 0.500 kg moving at 6.00 m/s strikes a wall normally and bounces back with a speed of 4.00 m/s. The mass was in contact with the wall for 0.200 s.
Find:
a) the change of momentum of the mass
b) the average force the wall exerted on the mass
delta P = m (V2-V1)
F = d/dt(mV) = m (V2-V1)/t
To find the change in momentum of the mass, we can use the formula:
Change in momentum = final momentum - initial momentum
The initial momentum of the mass can be calculated using the formula:
Initial momentum = mass × initial velocity
Therefore, the initial momentum is:
Initial momentum = 0.500 kg × 6.00 m/s = 3.00 kg·m/s
The final momentum of the mass can be calculated using the formula:
Final momentum = mass × final velocity
Therefore, the final momentum is:
Final momentum = 0.500 kg × (-4.00 m/s) = -2.00 kg·m/s
Now we can calculate the change in momentum:
Change in momentum = -2.00 kg·m/s - 3.00 kg·m/s = -5.00 kg·m/s
a) The change in momentum of the mass is -5.00 kg·m/s.
To find the average force exerted by the wall on the mass, we can use the formula:
Average force = change in momentum / time
Since we are given a time of contact of 0.200 s, we can substitute the values into the formula to find the average force:
Average force = -5.00 kg·m/s / 0.200 s = -25.0 N
b) The average force exerted by the wall on the mass is -25.0 N. The negative sign indicates that the force is directed towards the wall, opposite to the direction of motion of the mass.