Question

Momentum-1-During Complete the following problems in the Solution format. At the end of class, a problem will be selected at random. Please upload the solution for that problem to the assignment on Moodle. Problem 1: An object (2 kg) has several constant forces applied to it for 3 seconds. R = 58N, F2 = -28N, W = - 19.69 N. and Fg = 22.99 N. a) Find the impulse ). (Answer: 98 +9.99 Ns) b) If the initial velocity of the object was vo = 1 + 19, what is the velocity after the 3 seconds from the time that the forces are applied? (Answer: 5.52 +5.959) Problem 2: Suppose that you have an object of mass m, that experiences a net force of Fnet over a duration of At. The initial velocity of the object is zero and the final velocity is v. a) Write out the equation that relates all of these variables. b) What happens to the final velocity if you double the force? c) What happens to the final velocity if you double the duration of the force? d) What happens to the final velocity if you double the mass? c) Assuming that the change in momentum Ap is fixed, how could you reduce the required net force? Problem 3: A 1000 kg car travelling at 60 mph (26.8) impacts a brick wall. The car comes to a stop in At = 15 ms. a) What is the magnitude of the impulse i applied to the car? (Answer: 26,800 Ns) b) What is the magnitude of the net force applied to the car during the crash? (Answer: 1.79x10° N) c) A person with a mass of 75 kg is strapped into the car. What is the magnitude of the impulse applied to the person? (Answer: 2010 Ns) d) What is the magnitude of the net force applied person during the crash? (Answer: 134,000 N) c) What is the acceleration of the person during the crash in terms of g? Ig = 9.85 (Answer: 182g) Problem 4: How could we increase the survivability of the crash described in Problem 3? Why? Problem 5: A red cart has a mass of 0.5 kg and is initially moving with a velocity of Bro 38"A blue cart with a mass of 0.5 kg has an initial velocity of so = -38The carts collide with each other and bounce off, moving in opposite directions at constant velocities. The duration of the collision, when the constant net forces are applied, is given by At. a) Draw a FBD for each cart during the collision. b) What equation describes the net force on each cart? c) Write an equation for the change in momentum of each cart (Ap, and Apg). d) Write an equation that relates the change in momentum of the red cart to the change in momentum of the blue cart. e) Assume that the velocity of the red cart after the collision is on1 = -38the velocity of the blue cart after the collision is 11 = 38, and the time interval of the collision was At = 0.1 s. Find the forces that the carts put on each other during the collision.

Answer 1

Problem - 1 9)According to the condition given in question, We have limpulse), Sr.dk 3. • 5 * 3 - 2 x = 3(52 - 27) = 3 x 32 Now [impulse)y - Syndt = 419.6+22.9) 34 = +9.95 :: Impulse - (Q2 +9.99 ) Nos B) we have ū. (+ 9.95 ) mis. Consider equation of motion. r = ut at Va = " + aut. = 5-2 x = x + 3 = x 3. 1ã + 4.5a vx = 5.52 Vy = uy tayt - 18 (22.9-19.6

Now = 5.955 Now I ara + Ty ū . (5.57 + 5.955 ) mis. V