Question

I need help on these questions thank you so much

Vic = 40 m/s Vy = -10 m/s 4c = -6 m/s2 170 m 1. Chris is driving at the initial speed of 40 m/s. Then he sees a tumbleweed approaching him at 10 m/s, 170 m away from him. He immediately steps on the brake, decelerating at ac = -6 m/s? How long will it take for the car to collide with the tumbleweed? 2. A lawnmower of mass M = 6.5 kg moves across a lawn with a coefficient of friction Hk. The lawnmower is being pushed by a force, Fn = 36 N, along its handle which makes an angle 8 = 25° with the horizontal. If the lawnmower is moving at a constant velocity, what is the coefficient of friction, Uk? y = 5 m y = 0 --- yn § § y/2" ky = 223 N/m kg = 90 N/m 3. Two bowling balls, each with the mass of 7 kg, are dropped from 5 m above a pair of springs. The springs have the spring constants 223 N/m and 90 N/m, respectively. What will be the height difference in the two bowling balls' compressed positions? Assume that there's no air resistance.

Answer 1

Car s travelled by at time t = 40t - 1x 6xt" 2 = 40t -t s travelled by tumbleweed s= lot Sit S. = 170 50 +² - 3t² - 170 si >> 3-56+ + 170 = 0 52 te 50+ / 50% - 4x3x170 6. sot 21. 447 G 4758sec o 11- 907 8 sec feasible 4.95% see is because For, 11.9078see. VE 40-6 *// 9072 CO not feasible So, in 4 758see, it will collide.

2. M = 65 kg. For = 36N Ensino Fh V f 18 → Froso Mg Mg - Ensino NE 11 6.5X 98-36xsinas Fn Loso Mi N = 6.500 F oso = MEN 36xsinas] Me [ 6.5X9.8 36 Los 25 = MIC 36 * cosas = 0.672. 48.48 → MK = 0.672.

3. The Total potential Energy to Spring Energy. 7x9.8 x5 - 1x.223 Xv?, mgh = ) &,2 7x 9. 8X SX 2 223 - x = 1.733m.

Similarly, M2 = 7X9 8X SX 2 90 = N = 2.760m ke-, 1.0078m.