A ball of mass 0.3kg, moving at a velocity of 20ms-1 is suddenly hit by a force of 5N for a time of 0.03 sec. find its new velocity
F = ma, so a = F/m = 5/.3 = 16.7 m/s^2
so the new velocity will be Vo - at = 20 - .03*16.7 = 19.8 m/s
To find the new velocity of the ball, we can use Newton's second law of motion, which states that the force acting on an object is equal to the rate of change of its momentum.
Momentum (p) is calculated by multiplying the mass (m) of an object by its velocity (v). In equation form, it is expressed as p = m * v.
Since the ball is initially moving, it has an initial momentum given by p = 0.3 kg * 20 m/s = 6 kg·m/s.
The force acting on the ball is 5 N, and the time for which this force is applied is 0.03 seconds.
Now, we can calculate the change in momentum (∆p) using the formula ∆p = F * ∆t, where F is the force and ∆t is the time. Therefore, ∆p = 5 N * 0.03 s = 0.15 kg·m/s.
According to Newton's second law, ∆p is equal to the change in momentum of the ball, which can be written as ∆p = m * ∆v, where ∆v is the change in velocity.
Rearranging the equation, we have ∆v = ∆p / m.
Substituting the given values, ∆v = 0.15 kg·m/s / 0.3 kg = 0.5 m/s.
To find the new velocity (v'), we need to add the change in velocity (∆v) to the initial velocity (v). Therefore, v' = v + ∆v = 20 m/s + 0.5 m/s = 20.5 m/s.
Hence, the new velocity of the ball is 20.5 m/s.