Question

please explain the answers.

8) I was a scout when I was a young boy. Each year the scouts would participate in the pine wood derby (look up pine wood derby if don't know what that is). In the pine would derby you build a toy car out of a block of pine wood. Each scout then races their car in a competition, by letting their car go down a ramp. The rules of the pine wood derby dictate that a car can not be above a certain weight. Why would this constraint matter, after all the acceleration of an object due to gravity is independent of mass? 9) A ball of mass m is attached to the ceiling via a string of length L. The ball is given a push to set it in motion. The ball then travels in a horizontal circle, such that the string makes and angle with the vertical. It is observed that it takes time T for the ball to make one complete revolution. How can this experiment be used to measure the magnitude of the gravitational acceleration g. 10) A small mass m moves along a hoop of radius R without friction. Attached to the mass is a spring with spring constant k. The other end of the spring is attached to the bottom of the hoop. The equilibrium length of the spring is 0 and the force from the spring on the bead is kr. The mass is placed at the bottom of the hoop and given an initial speed to the right of vo. What is the minimum value of vo so that the mass can make full revolution of the hoop?

Answer 1

8.) If the car would be of more weight that means it will have more momentum. So, it will be very hard to stop it in case of any mishap. It will also poise a threat to the safety of the audience. Moreover, more weight means more amount of wood needed, whiich means felling of more trees. So, weight limit is put on.

9.) The x-component of the tension in the string will be equal to the centrifugal force. And the y-component of the tension in the string will be equal to m*g. Solving these equations, g can be calculated.

☺ an Angular velocity of ball a 24 o V = Lsino mewn=€ ing For sino = mowe & Fr= in Lainox ( 24 ) ² sino Fy = mL x(24) 2 Ef cono = ing ng f of the l *)6020 = g = ! como las )? g m/s2

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