167.Samolet weight of 5 tonnes. Moves in the horizontal direction at a speed km / h. He then rose to a height h = 2 km. The velocity of the aircraft has decreased to km / h. Find the work expended to lift the aircraft engine without taking into account the work to overcome the air.
168.S tower height H = 25 m horizontally threw a stone at a speed of m / s. Find the kinetic and potential energy of rock with later after the beginning of the fall. Weight 0.2 kg stone. Air resistance neglected. Potential energy is zero take at ground level.
169.Kamen weighing 0.3 kg dropped from a tower in a horizontal initial velocity. After the stone was to speed with the angle of the horizon. Find the kinetic energy of the stone at this point.
170.Mayatnik is a heavy ball suspended on a weightless and inextensible thread length. The pendulum was dismissed from the vertical at an angle and then released. What is the highest speed will get the ball?
149.Poezd weighing 388 tons, and left the station, moving with constant acceleration during the path traveled 200 m. Determine the power of the engine, to develop at the end of the 40th second, if the coefficient of friction of the wheels on the rails is equal to 0.006.
150.Samolet for take-off should be the speed of 25 m / s. The path length of 100 m before taking off. What is the average power of the motor, if the mass of the aircraft of 1000 kg and the coefficient of resistance to movement k = 0.02?
151.Motory locomotive at a speed of 72 km / h consumes power N = 800.000 watts. The efficiency of the electric propulsion system 0.8. Determine the traction motor.
152.Kakoy inclined lift can overcome the power of 370,000 watts locomotive moving AMIS 2000.000 kg at a speed of 7.2 km / h when the friction coefficient k = 0.002? Read the angle of the railway line to the horizon small.
54. What is the height of the river bank when a stone fell from the shore reached the surface of the water through 3. What is the final velocity of the stone?
55.Svobodno falling body at the moment of hitting the ground reached a speed of 39.2 m / s. From what height fallen body? How long will it fall?
56.Sportsmen jumping from the tower into the water. As far as the resistance increases the incidence, if the tower height of 10 m, and with the fall 1b8.
57.Telo dropped from a height of 4.9 m. What was the average speed of the body? What speed was the body of a fall to the floor.
58.Odno body falls from a height of 20 m, 80 m and the second. How many times the rate of fall to the ground a second greater than the speed of falling body of the first body? How many times during the fall of the second body more time to fall first?
108. Body mass m moves upward along the vertical wall by the force F, directed at an angle to the vertical. Determine the acceleration of the body.
109.Gruz mass of 500 kg is pushed to the vertical wall strength of 100 N. What is the force needed to pull the load evenly and vertically to hold the load alone if the friction coefficient k = 0.3?
110.Avtodrezina lucky uniformly accelerated two platforms. Tractive force F1 = 1,79 kN. Mass of the first platform 12 m, the second - 6 m. With a strained grip force F2 between platforms.
132. The shell 50 kg 300 flying at an angle to the vertical, at a speed of 800 m / s misses the platform loaded with sand and stuck therein. Find the speed of the platform after a shell hit if its mass M = 16 tons.
133.Chelovek standing skating on the smooth ice throws a stone with a mass of 0.5 kg. After a time, 2 stone reaches the shore, passing a distance of 20 m. With a speed skater starts to slide, if its mass M = 60 kg. Friction skates and stone on the ice is not taken into account.
134.Telo mass M = 990 kg rests on a horizontal surface. It gets a bullet weighing 10 grams and gets stuck in it. Bullet velocity is directed horizontally and is 700 m / s. Which path will take the body to a stop, if the coefficient of friction