A 7.5 Kg cannon ball leaves a canon with a speed of 185 meters per second. Find the average net force applied to the ball is the canon muzzle is 3.6 meters long

F = 35651 [N]

Explanation:

To solve this problem we must use the following equation of kinematics

where:

Vf = final velocity = 185 [m/s]

Vo = initial velocity = 0 (starts from the rest)

a = acceleration [m/s²]

x = distance = 3.6 [m]

Now we can find the acceleration.

185² = 0 + 2*a*3.6

34225 = 7.2*a

a = 4753.47 [m/s²]

Now we must use Newton's second law which tells us that the total force on a body is equal to the product of mass by acceleration.

F = m*a

where:

m = mass = 7.5 [kg]

F = force [N] (units of Newtons)

F = 7.5*4753.47

F = 35651 [N]

-4 on

the minimum constant speed at which she can catch the train is 2.7 m/s

given:

acceleration = 0.6

time = 4.5 s

to find:

velocity = ?

formula used:

from 1st kinematic equation we get,

v = u + at

u = initial speed of train = 0 m/s

v = final speed of the train

a = acceleration of the train

t = time

solution:

from 1st kinematic equation we get,

v = u + at

u = initial speed of train = 0 m/s

v = final speed of the train

a = acceleration of the train

t = time

v = 0 + (0.6 × 4.5)

v = 2.7 m/s

the minimum constant speed at which she can catch the train is 2.7 m/s