The outside temperature is 25 °C. A heat engine operates in the environment (Tc = 25 °C) at 50% efficiency. How hot does it need to get the high temperature up to in Celsius?

Gas is compressed in a cylinder creating 31 Joules of work on the gas during the isothermal process. How much heat flows from the gas into the cylinder in Joules?

The heat engine gives 1100 Joules of energy of high temperature from the burning gasoline by exhausting 750 Joules to low-temperature . What is the efficiency of this heat engine in a percentage?

L₁ D₁ L₂ D2 Aluminum has a resistivity of p = 2.65 × 10 8 2. m. An aluminum wire is L = 2.00 m long and has a circular cross section that is not constant. The diameter of the wire is D₁ = 0.17 mm for a length of L₁ = 0.500 m and a diameter of D2 = 0.24 mm for the rest of the length. a) What is the resistance of this wire? R = Hint A potential difference of AV = 1.40 V is applied across the wire. b) What is the magnitude of the current density in the thin part of the wire? Hint J1 = c) What is the magnitude of the current density in the thick part of the wire? J₂ = d) What is the magnitude of the electric field in the thin part of the wire? E1 = Hint e) What is the magnitude of the electric field in the thick part of the wire? E2 =

please help

A cheetah spots a gazelle in the distance and begins to sprint from rest, accelerating uniformly at a rate of 8.00 m/s^2 for 5 seconds. After 5 seconds, the cheetah sees that the gazelle has escaped to safety, so it begins to decelerate uniformly at 6.00 m/s^2 until it comes to a stop.

A projectile is fired with an initial speed of 40.2 m/s at an angle of 35.0 degree above the horizontal on a long flat firing range. Determine. please help and show work for them so i can understand.

pls help

J K L The graph in the figure shows the position of an object as a function of time. The letters H-L represent particular moments of time. At which moments shown (H, I, etc.) is the speed of the object the greatest? + Position H I K Time