3 a 2 kg mass is traveling in the forward direction with a...

3. A 2 kg mass is traveling in the forward direction with a speed of 3 m/s. It receives an impulse in the forward direction of 4 kg m/s over a time period of 5 seconds. What is the object's speed after those 5 seconds? a) 5 m/s b) 7 m/s c) 10 m/s d) 26 m/s 4. A clay ball and a rubber ball of equal masses are falling towards the ground with the same initial velocity. The clay ball sticks to the ground and the rubber ball bounces upwards after hitting the ground. Which of the following is true? a) the ground exerts a larger impulse on the clay ball than it does on the rubber ball b) the ground exerts a larger impulse on the rubber ball than it does on the clay ball c) the ground exerts the same impulse on the clay ball as it does on the rubber ball d) it depends on the speed of the balls 5. John (mass 50 kg) is standing in a boat (mass 70 kg) and holding an anchor (30 kg). He throws the anchor horizontally forwards with a speed of 2 m/s. What will happen to John and the boat? a) they will remain stationary b) they will travel backwards with an initial speed of 2 m/s c) they will travel backwards with an initial speed of 0.5 m/s d) they will travel backwards with an initial speed of 4 m/s

Transcript

00:01 Hello students in this question there are three parts and in the first part of the question an object is been given whose final velocity b has to be determined and in order to find the value of b a few data are been given which include mass of the object m to be equal to 2 kilogram its initial velocity u is taken to be 3 meter per second and impulse j is taken to be a value of 4 kilogram meter per second now in order to find the value of this final velocity we need to use the impulse momentum equation which is taken as j to be equal to change in momentum delta p that is equal to mass m into final velocity b minus initial velocity u and here by substituting the value of j m and you in this equation our equation changes as 4 to be equal to 2 into b minus 3 from which we get the value of final velocity of the object b to be equal to 5 meter per second therefore among the options given here option a is the right answer.

01:01 Now in the second part of the question two balls are being given which are a clay bowl and a rubber bowl and according to the question mass of clay bowl mc will be equal to mass of rubber bowl m are which is equal to a common mass small letter m on the other hand the initial velocity of clay ball uc will be equal to the initial velocity of rubber ball u which is equal to a common initial velocity small letter u and here according to the impulse momentum equation we get impulse j to be equal to change in momentum delta p.

01:34 Now for the case of the clay ball, this equation changes as change in momentum delta pc will be equal to mass m into final velocity of the clay vc minus initial velocity uc.

01:47 And here it is given that the value of vc is taken to be 0 meter per second.

01:52 Thereby our equation changes as delta p c to be equal to minus m into uc let this be equation number one on the other hand for the rubber ball the equation changes as delta pr to be equal to mass m into vr minus of minus m into u r and here it is given that the value of vr will be equal to the value of u r that is equal to a common velocity small letter v thereby our above equation changes as delta pr to be equal to a value of 2m into v.

02:29 Let this be equation number 2.

02:31 And here from equation number 1 and equation number 2 we can say that the ground exerts more impulse on the rubber ball.

02:51 Therefore among the options given here, option b is the right answer.

02:55 Now in the third part of the question, it is given that john is standing in a boat.

03:00 Here we need to find out the finite velocity of john and boat which is taken as small letter fee.

03:06 And in order to find the value of this final velocity, a few data are being given which include mass of john, mj to be equal to 50 kilogram, mass of the boat mb to be equal to 70 kilogram and mass of the anchor m .a to be equal to 30 kilogram.

03:25 Now in this question it is given that the final velocity of the anchor is taken as va which is equal to 2 meter per second, while its initial velocity is taken as ua, which is equal to 0 meter per second...

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