Question

1 A ball of mass 0.50 kg is thrown with speed of 10 m/s. A stationary
receiver catches the ball and bring it to rest in 0.02 second.
Calculate
i) Impulse delivered to the ball
ii) average force exerted on the receiver​

Answer 1

Answer:

A ball of mass 0.50 kg is thrown with speed of 10 m/s. A stationary

receiver catches the ball and bring it to rest in 0.02 second.

Calculate

i) Impulse delivered to the ball

ii) average force exerted on the receiver

Answer 2

• Impulse in Physics is a term that is used to describe or quantify the effect of force acting over time to change the momentum of an object. It is represented by the symbol J and is usually expressed in Newton- seconds or kg m/s. Mathematically it is written as :

                                 Impulse J = ΔP

                                                  = |P₂ - P₁| ...............(i)

                where P₂ = Final Momentum

                            P₁ = Initial Momentum

                            T =  time taken

Also, Average force  = Change in Momentum / time

Given,

• mass m = 0.50 kg
• initial velocity u = 10m/s
• final velocity v = 0 (as the ball was caught and stopped)
• time t = 0.02s

Substituting Momentum P = Mass * Velocity

                                    or P = mv in equation (i)

we get,

                     Impulse J = | mv - mu |

                                      = m | v - u |

                                      =   0.50 * | -10 |

   (i)          ⇒ impulse J  = 5 kg m/s      

    (ii)     We know ,

                      Average force = Change in Momentum / time

                                                = | mv - mu | / t

                                                = m | v - u | / t

                                                = $\frac{0.50 * |-10|}{0.02}$

                  ⇒ Average force = 250 N