Fundamentals of Physics + time - math problems

Number of problems found: 122

Up and down motion
We throw the body from a height h = 5 m above the Earth vertically upwards v0 = 10 m/s. How long before we have to let the second body fall freely from the same height to hit the Earth at the same time?
Train delay
Due to a breakdown, the train lost 16 minutes of standing on the track behind Brno. He "eliminated" this delay so that after the start, the 80 km long section went at a speed 10 km/h higher than originally planned. What speed was it and what was it suppos
Candles
Before Christmas, Eva bought two cylindrical candles - red and green. Red was 1 cm longer than green. She lit a red candle on Christmas Day at 5:30 p. M. , lit a green candle at 7:00 p. M. , and left them both on fire until they burned. At 9:30 p. M. , bo
Motorcycle engine
The motorcycle engine has a constant power of 1.2 kW for 0.5 hours. How much work does the engine do? Express work in kWh and Ws units.
On a
On a some day, the Sun, Venus and the Earth are in eclipse, i. E. Venus is between the Sun and the Earth. Venus orbits the Sun in 225 days. In how many years will all three bodies be in alignment again?
Electric work
Calculate the work done by the electric forces passing the current of 0.2 A through the bulb in 10 minutes if the bulb is connected to a 230 V power supply.
The coal
The coal stock would be enough to heat a larger room for 12 weeks, a smaller one for 18 weeks. It was heated for four weeks in both rooms, then only in a smaller one. How long was the coal stock enough?
A particle
A particle moves in a straight line so that its velocity (m/s) at time t seconds is given by v(t) = 3t²-4t-4, t>0. Initially the particle is 8 meters to the right of a fixed origin. After how many seconds is the particle at the origin?
Cooker
A current of 2A passes through the immersion cooker at a voltage of 230V. What work do the electric field forces in 2 minutes?
The shooter
The shooter heard the impact of the bullet on the target in one second after the shot. The bullet was moving at an average speed of 500 m/s. Calculate with speed of sound of 340 m/s. Determine the distance of the target.
Self-oscillation period
The water in the vessel carried by the boy has a self-oscillation period of 0.8 s. What is the size of the boy's movement speed when the length of the boy's step is 60 cm? Give the result in m/s.
The run
On the school playground, the student ran a 60 m track in 9.5 s. What is the average speed of his run?
Water current
John swims upstream. After a while, he passes the bottle, from that moment he floats for 20 minutes in the same direction. He then turns around and swims back, and from the first meeting with the bottle, he sails 2 kilometers before he reaches the bottle.
Cheetah vs antelope
When the cheetah began chasing the antelope, the distance between them was 120 meters. Although the antelope was running at 72km/h, the cheetah caught up with it in 12 seconds. What speed was the cheetah running?
Cyclists and walkers
A group of tourists started at 8:00 at speed 4 km/h walk. At half-past ten, another group started on a bike and caught up with a group of tourists at 10:50. What was the average speed of cyclists?
Where and when
The truck left Kremnica at 11:00 h at a speed of 60km/h. At 12:30 h, the passenger car started at an average speed of 80km/h. How many kilometers from Kremnica will the passenger car reach the truck, and when?
Positional energy
What velocity in km/h must a body weighing 60 kg have for its kinetic energy to be the same as its positional energy at the height 50 m?
The tourist
The tourist traveled 78km in 3 hours. Part of the journey went on foot at 6km/h, the rest of the trip by bus at 30km/h. How long did he walk?
Car loop
The toy car runs at an average speed of 2 m/s. In a minute, it will pass the entire circuit five times. How long is the loop?
Two friends
Two friends on a bicycle rode against each other from two places 49 km apart. The first set off at 8.00 at a speed of 20km/h, the second 12 minutes later at a speed of 25km/h. What time do they meet? How many km will each of them travel since then?