Một vật khối lượng m được kéo trượt trên sàn bằng lực kéo F tạo góc α so với phương ngang. Biết hệ số ma sát với sàn là µ.
a. Tìm gia tốc của vật với α = 0, µ = 0,01, m = 1kg, F = 2N
b. Với α = 0, µ = 0,01, m = 1kg, muốn vật đi đều thì F = ?
c. Với α = 0, µ = 0,01, m = 1kg, muốn vật sau khi xuất phát 50m có vận tốc 36 km/h thì F = ?
d. Tìm gia tốc của vật khi α = 300, µ = 0,01, m = 1kg, F = 2N.

Identical marbles are released from the same height on each of the following four frictionless ramps . compare the speed of the marbles at the end of each ramp. explain your reasoning

Asteam power plant operates on an ideal reheat rankine cycle between the pressure limits of 15 mpa and 10 kpa. the mass flow rate of steam through the cycle is 12 kg/s. steam enters both stages of the turbine at 500°c. if the moisture content of the steam at the exit of the low-pressure turbine is not to exceed 10 percent, determine (a) the pressure at which reheating takes place, (b) the total rate of heat input in the boiler, and (c) the thermal efficiency of the cycle. also, show the cycle on a t-s diagram with respect to the saturation lines. (2.15 mpa; 45.0 mw; 42.6%)

Two horses begin at rest. after a few seconds, horse a is traveling with a velocity of 10 m/s west, while horse b is traveling with a velocity of 13 m/s west. which horse had a greater acceleration? a. horse a because its change in velocity was greater than horse b's in the same time. b. horse b because its change in velocity was greater than horse a's in the same time. c. horse b because its change in velocity was the same as horse a's, but it took less time. d. both horses had the same acceleration.