An electric kettle has a power rating of 2.4kW. How long does it take the kettle to heat up 4.5kg of tap water from 28°C to 100°C ? (c of water = 4200Jkg1°C-) What assumption must you make to arrive the answer ? pls helppp

An important dimensionless parameter concerned with very high-speed flow is the mach number, defined as v/c, where v is the speed of the object such as an airplane or projectile, and c is the speed of sound in the fluid surrounding the object. for a projectile traveling at 1170 mph through air at 50 ˚f and standard atmospheric pressure, what is the value of the mach number?