Fundamentals of Physics - examples - page 7
- The swimmer
The swimmer swims at a constant speed of 0.85 m/s relative to water flow. The current speed in the river is 0.40 m/s, the river width is 90 m. a) What is the resulting speed of the swimmer with respect to the tree on the riverbank when the swimmer motion
The driver of the car at a speed of 100 km/h faced the obstacle and began to brake with a slowing of 5 m/s². What is the path to stopping the car when the driver has registered the obstacle with a delay of 0.7 s?
A 60 W bulb consumes 0.12 kWh of electricity. How long did she stand light without a break?
- Two ships
The distance from A to B is 300km. At 7 am started from A to B a ferry with speed higher by 20 km/h than a ship that leaves at 8 o'clock from B to A. Both met at 10h 24min. Determine how far they will meet from A and when they reach the destination.
- Free fall
The free fall body has gone 10m in the last 0.5s. Find the body speed at the moment of impact.
- Car overtaking
A passenger car travels at a speed of 30 m/s, and before it travels freight truck that drives at a constant speed of 10 m/s. Within 30 meters of the truck, the driver of the car finds out that the truck can not overtake. That's why it starts braking with a
After the parachute is opened, the paratrooper drops to the ground at a constant speed of 2 m/s, with the sidewinding at a steady speed of 1.5 m/s. Find: a) the magnitude of its resulting velocity with respect to the ground, b) the distance of his land fr
- Outside temperature
The temperature outside was 57 degree Fahrenheit. During the next few hours it decreased by 18 degrees and then increased by 23 degrees. Find new temperature.
- Iron density
Calculate the weight of a 2 m long rail pipe with an internal diameter of 10 cm and a wall thickness of 3 mm. The iron density is p = 7.8 g/cm3.
- A car
A car weighing 1.05 tonnes driving at the maximum allowed speed in the village (50 km/h) hit a solid concrete bulkhead. Calculate height it would have to fall on the concrete surface to make the impact intensity the same as in the first case!
The two bodies, whose initial distance is 240 m, move evenly against each other consistently. The first body has an initial velocity of 4 m/s and an acceleration of 3 m/s2, the second body has an initial speed of 6 m/s and an acceleration of 2 m/s2. Find
- Car crash
On the road, with a maximum permitted speed of 60 km/h, there was a car crash. From the length of the vehicle's braking distance, which was 40 m, the police investigated whether the driver did not exceed that speed. What is the conclusion of the police, as
Imagine that a unit of air at a temperature of 25°C rises up a mountain range that is 3,000 meters high on the windward side and which descends to 1,200 meters on the leeward side, assuming that the air will remain dry what will its temperature when it cro
- Two vans
At 8:30 a. M. , two vans leave at a parking area. They travel in opposite directions: one van travels at 48 km/h and the other at 62 km/h. At what time will the cars be 550 km apart?
- Air thermal
Imagine that a unit of air rises at 3000 meters high, if temperature decreases 6 degrees celcius for every 1000 meter, what will be its temperature at 1400 meters, 2000 meters, 2500 meters and when it reaches the 3000 meter elevation. Starting temperature.
The braking efficiency of a passenger car is required to stop at 12.5 m at an initial speed of 40 km/h. What is the acceleration braking by brakes?
- MW oven
You plug a microwave oven into a 20 amp electrical circuit. the microwave uses as much as 12.5 amps . How many amps are available on this circuit for other appliances?
- Dirty road
Mr. Smith is on a road trip to a remote disc golf course 180km away. He travels part of the way at 100km/h along the highway, and part of the way at 50km/h along dirt roads. If it took 2 hours to get there, how many hours did he spend on dirt roads?
Lucie can walk about 3 4/5 miles each hour. How far can she walk in 2 hours 45 minutes?
- Pre účinnosť
Pre účinnosť bŕzd osobného vozidla je predpísané, že automobil pohybujúci sa po vodorovnej vozovke rýchlosťou 40km. H musí zastaviť na dráhe 15,4 m. Aké veľké je pritom spomalenie automobilu?