Fundamentals of Physics - examples
- Thunder and lightning
There was a glimpse of the sky and we hear a thunder in 4.5 seconds. The light spreads at 300,000 kilometers per second, so we can assume the flash instantly without delay. However, the speed of the sound is much smaller in the air one third of a kilomete
- Eiffel Tower
Eiffel Tower in Paris is 300 meters high, is made of steel. Its weight is 8000 tons. How tall is the tower model made of the same material, if it weigh is 4.8 kg?
- Widescreen monitor
Computer business hit by a wave of widescreen monitors and televisions. Calculate the area of the LCD monitor with a diagonal size 37 inches at ratio 4:3 and then 16:9 aspect ratio. Is buying widescreen monitors with same diagonal more advantageous tha
In point X acts three orthogonal forces: F1 = 13 N, F2 = 8 N and F3 = 15 N. Determine the resultant of F and the angles between F and forces F1, F2 and F3.
- Reconstruction of the corridor
Calculate how many minutes will be reduced to travel 192 km long railway corridor, where the maximum speed increases from 120 km/h to 160 km/h. Calculate how many minutes will shorten travel time, if we consider that the train must stop at 6 stations, eac
From the cottage started first group of tourists at 10:00 AM at speed 4 km/h. The second started after them 39 minutes later at speed 6 km/h. How long and how many kilometers from the cottage will catch the first group?
- Reservoir + water
Reservoir completely filled with water weighs 13 kg. After pouring off three quarters of the amount of water weights 4 kg. Calculate the weight and volume of the reservoir.
- Two forces
Two forces with magnitudes of 25 and 30 pounds act on an object at angles of 10° and 100° respectively. Find the direction and magnitude of the resultant force. Round to two decimal places in all intermediate steps and in your final answer.
The train is running at speeds of 84 km/h. From the beginning of braking to full stop train run for 3.4 minutes. If the train slows the braking equally, calculate the distance of the place from the station where you need to start to brake.
- Hollow sphere
Steel hollow sphere floats on the water plunged into half its volume. Determine the outer radius of the sphere and wall thickness, if you know that the weight of the sphere is 0.5 kg and density of steel is 7850 kg/m3
- Two runners
Two runners ran simultaneously towards each other from locations distant 21 km. The average speed of the first runner was 1/7 higher than the average speed of the second runner. How long should each ran a 21 km, if you know that they meet after 77 minute
What is the average speed of the car, where half of the distance covered passed at speed 59 km/h and the other half at 119 km/h.
- BMI index
Calculate BMI (body mass index, an index indicating obesity, overweight, normal weight, underweight) man weighing m = 79 kg and height h = 193 cm. Index is calculated according to equation (formula): ? With BMI index is possible to compare people of diff
- Circular motion
Mass point moves moves uniformly in a circle with radius r = 3.2 m angular velocity ω = 4.3 rad/s. Calculate the period, frequency, and the centripetal acceleration of this movement.
- Motor physics
Car traveling at 97 km/h on the highway. Pulling power of the motor is 6 kN. Determine engine power in kW.
Parents piggybacking children on vacation to its grandmother and grandfather at a city distant 150 kilometers. They agreed to meet halfway. Parents will be travel at 90 km/h, grandmother and grandfather at 60 km/h. Parents depart at 12:00 hours. When grand
Stone was pushed into the abyss: 7 seconds after we heard hitting the bottom. How deep is the abyss (neglecting air resistance)? (gravitational acceleration g = 9.81 m/s2 and the speed of sound in air v = 337 m/s)
The driver of a car is to get to 378 km distant city. From atlas found that 99 km will have to pass through the cities at average speed 48 km/h. Remainder of the journey pass outside the cities at average speed 117 km/h. Calculate how many hours it will ta
The first racer run at a speed 12 m/s and is 470 meters before the finish and ahead 22 meters before second competitor. At what speed must run the second racer to catch first racer at the finish line?
- Cuboid 5
Calculate the weight of the cuboid with dimensions of 12 cm; 0.8 dm and 100 mm made from spruce wood (ς = 550 kg/m3).