An object is placed on the moveable piston of a cylinder filled with a gas. The object exerts a downward force F on the piston that accelerates the piston downward, compressing the gas. Which of the following is a correct description of the magnitude of the upward force exerted by the piston on the object? a. The force exerted by the piston on the object is equal to FF.
b. The force exerted by the piston on the object is less than FF because the piston is accelerating downward.
c. The force exerted by the piston on the object is greater than F because the gas exerts an upward force on the piston.
d. The force exerted by the piston cannot be compared to FF without knowing the magnitude of the acceleration of the piston and pressure of the gas.

We want to calculate the total metabolic heat generated by a singing canary taking into account heat transfer by radiation, convection and exhaling air. the air temperature is 20 oc, canary’s body internal and surface temperature is 33oc, external body surface convective heat transfer coefficient is 25.2 w/m2 .k, temperature difference between the inhaled and exhaled air is 4.3 oc, the ventilation rate is 0.74 cc of air per second, specific heat of air is 1.0066 kj/kg. k and density of air is 1.16 kg/m3 . assume the canary’s body to be a cylinder with 7 cm diameter and 9 cm length, and heat exchange is from the side as well as the top and bottom of cylinder. calculate 1) the net rate of heat lost by radiation, assuming heat gained by the bird through radiation from the surroundings is 11.5 w; 2) rate of heat transferred by convection to the surrounding air; 3) rate of heat transferred in the exhaling air without considering any internal evaporation; 4) total metabolic power.

Samir watches a 100-minute movie on his spaceship. maria's spaceshipe flies in the same direction as samir's spaceship but she observes his move to last 125 minutes and his spaceship to be 40 m long. how long does samir observe his own spaceship to be? according to an observer on earth, planet x is stationary. maria and samir depart earth on their spaceships at the same time, each flying at 0.5c. maria flies toward planet x and samir flies in the opposite direction. according to maria, her voyage to planet x takes 9 years. how many years does marias voyage take according to samir?

What is the average speed of a car that travels 40mph for 1 hour and 60 mph in another hour will mark brainliest