(a) a car speedometer has a 5.0% uncertainty. what is the range of possible speeds when it reads 90km/h? (b) convert this range to miles per hour. (1 km=0.6214 mi)

Sarah and michelle work at a tech company that designs exercise apps. sarah tells michelle she has heard that james, their supervisor, interviewed with a competitor and may be leaving the company, which would open up a management position. what kind of power is sarah exerting?

It's a snowy day and you're pulling a friend along a level road on a sled. you've both been taking physics, so she asks what you think the coefficient of friction between the sled and the snow is. you've been walking at a steady 1.5m/s, and the rope pulls up on the sled at a 32 ∘ angle. you estimate that the mass of the sled, with your friend on it, is 65 kg and that you're pulling with a force of 80 n .

Arefrigerator uses r-134a as the working fluid and operates on the ideal vapor-compression refrigeration cycle except for the compression process. the refrigerant enters the evaporator at 120 kpa with a quality of 34 percent and leaves the compressor at 70°c. if the compressor consumes 450 w of power, determine (a) the mass flow rate of the refrigerant, (b) the condenser pressure, and (c) the cop of the refrigerator. (0.00644 kg/s, 800 kpa, 2.03)