A ball of mass 100 g moving with a velocity of 20 ms-1 is brought to rest in 0.02 s. The average force on the ball is ____.
Force = change in momentum / change in time
= .1 * 20 / .02
= 100 N
100n
mujhe kuch nahi aata
To find the average force on 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. Mathematically, we can express this as:
Force = (Change in momentum) / (Time taken)
First, let's calculate the initial momentum (p_i) of the ball. Since momentum is the product of mass (m) and velocity (v), we have:
p_i = m * v
Plugging in the values given: m = 100 g = 0.1 kg and v = 20 m/s, we get:
p_i = 0.1 kg * 20 m/s = 2 kg m/s
Next, we can calculate the final momentum (p_f) of the ball. Since the ball is brought to rest, its final velocity (v_f) is 0 m/s. So we have:
p_f = m * v_f = 0.1 kg * 0 m/s = 0 kg m/s
Now, let's calculate the change in momentum (Δp), which is the difference between the initial and final momenta:
Δp = p_f - p_i = 0 kg m/s - 2 kg m/s = -2 kg m/s
Finally, we can calculate the average force (F) on the ball using Newton's second law. The time taken (t) is given as 0.02 s:
F = Δp / t = -2 kg m/s / 0.02 s = -100 N
Therefore, the average force on the ball is -100 N.
Note: The negative sign indicates that the force is acting in the opposite direction of the ball's motion, which is necessary to bring it to rest.