Un automóvil se desplaza a una velocidad de \( 90 \mathrm{~km} / \mathrm{h} \) y para mantener esta velodidad debe vencer a un conjunto, de fuerzas equivalentes a 2400 N . Determina la potencia desarrollada (expresada en CV.) hecha por el automóvil en un recorrido de 10 km y en un tiempo de 400 segundos. a. 60 CV b. \( 293,48 \mathrm{CV} \) c. 60000 CV d. \( 81,5 \mathrm{CV} \)

Una esfea de Jan esta unifarmanate cargada con una densidad de carga de \( \frac{1.2 \times 10^{-5}}{\pi} \frac{\mathrm{c}}{\mathrm{m}^{3}} \). Calcular el modo del campo electrico a una distancia centro, en el interior \( (r<5) \) y en el exterior \( (r>5) \).

- Cuál es el área mínima de un bloque de hielo flatando en el ugua para poder sustentar a un aulomóvil que pesa 1200 kg f?. El bloque tiene una altura de \( 2 \mathrm{~mm} .\left(\rho_{\text {hielo }}=0,9 \mathrm{gf} / \mathrm{cm}^{3}\right) \).

A box sitting on a horizontal surface is attached to a second box sitting on an inclined ramp by a rope that passes over an ideal pulley. The rope exerts a tension force I on both weights along the direction of the rope, and the coefficient of friction between the surface and boxes is 0.6 . If the box on the right weighs 100 pounds and the angle of the ramp is \( 35^{\circ} \), how much must the box on the left weigh for the system to be in static equilibrium? The box on the left must weigh approximately \( \square \) pounds for the system to be in static equilibrium. (Do not round until the final answer. Then round to two decimal places as needed.)

1. If you were to visit a planet that was much more massive than earth, your mass would be a) More b) Less c) The same d) Impossible to tell without knowing which planet you are visiting. 2. Which of the following is not a form of light? a) radio waves b) microwaves c) x-rays d) All of the above are a form of light. e) None of the above is a form of light

3. You cannot tell whether an object is in motion unless you ha frame of reference. 4. A frame of reference is some other object to which you comp an object's position. 5. When scientists study the motion of stars in the sky, they use clouds as a frame of reference.