The force needed to keep a car from skidding on a curve varies Inversely as the radius of the curve and jointly as the weight of th car's speed. Suppose that 200 pounds of force keeps a 3200 -pound car from skidding on a curve of radius 400 ft at 25 mph . What car from skidding on a curve of radius 550 ft at 55 mph ? pounds of force

A bullet is fired at an angle of \( 30^{\circ} \) to the horizontal at a velocity of \( 400 \mathrm{~m} / \mathrm{s} \) Calculate the following: 1.2 .1 The maximum height reached by the bullet 1.2 .2 The horizontal displacement when the bullet hits the ground

travel at without slipping? A car travels at a constant speed in a circular path of 120 m radius. It completes one circuit in 23 s . If the ground is level, what is the minimum coefficient of friction between the tires and the road?

3) Se sabe que la aceleración (a) se define como el cambio de la velocidad \( (v) \) en el tiempo (t), entonces \( a=\frac{d}{d t} v \), si la velocidad en cierto sistema está determinada por: \( v(t)=t^{2}-5 t \) a) ¿Cuál será el tiempo en el cual la velocidad es constante? \( v(t)=-S \)

The brightness of a light bulb changes inversely with resistance and directly with voltage. What is the new resistance if a 60 -watt, 120 -volt bulb is used in place of a 100 -watt, 120 -volt bulb with 144 ohms?

52. A certain planet has a mass of \( 3.3 \times 10^{23} \mathrm{~kg} \) and a adjus of \( 2.6 \times 10^{6} \mathrm{~m} \). What is the acceleration due to gravity on the surface of this planet? a. \( 0.54 \mathrm{~m} / \mathrm{s}^{2} \) b. \( 3.3 \mathrm{~m} / \mathrm{s}^{2} \) c. \( 4.0 \mathrm{~m} / \mathrm{s}^{2} \) d. \( 9.8 \mathrm{~m} / \mathrm{s}^{2} \)