Imagine a Carnot engine has a hot reservoir of 680 K and a cold reservoir of 220 K. What is the efficiency of the engine?

What is true for ALL of the examples of electromagnetic waves? A) They all move at the same speed in a vacuum. B) They all have the same wavelength. C) They all have the same frequency. D) They all have the same energy.

A girl cycles for 2 hours at a speed of 25 km/hr. What distance did she travel?

Which statement describes the relationship between chromosomes, genes, and alleles? a. Alleles are sites on a chromosome that genes bind to. b. A chromosome's specific section is called a gene. Alleles are variations of a gene. c.

Consider a high pressure system with a value of 1045mb and a low pressure system with a value of 997mb. The two pressure systems are 250 km apart. The pressure gra the two pressure systems is: A. 48mb/250km (0.19mb/km) B. 250mb/48km (5.21mb/km) C.

In all ecosystems energy is eventually lost to the environment via

Light from the sun travels through space to Earth's atmosphere. Which will light waves do when they move from empty space into matter made up of different gases? A. move at the same speed B. move faster as they transmit C. slow down and refract D.

A 12.5 kg box sliding on a frictionless flat surface tuns into a fixed spring which compresses at a distance x = 14.1 cm. the spring constant is 94.5 kN/m Find the initial speed of the box

An earth scientist who studies hydrosphere

In 1991 four English teenagers built an eletric car that could attain a speed of 30.0m/s. Suppose it takes 8.0s for this car to accelerate from 18.0m/s to 30.0m/s. What is the magnitude of the car's acceleration?

A capacitor with a capacitance of 490 μf is charged to a voltage of 260 v. then a wire is connected between the plates. how many joules of thermal energy are produced as the capacitor