Fundamentals of Physics - 9th grade (14y) - practice problems
Number of problems found: 161
The car runs on a horizontal track at a constant speed of 20 m2-1. It is raining. Raindrops fall in a vertical direction at a speed of 6 m/s. a) How fast is the speed of the drops relative to the car windows? b) What is the angle of the raindro
- Brian 2
Brian and Jake left their homes, which are 500 miles apart, and drove straight toward each other. It took 4 hours for the two to meet if Jake's speed was 15 mph slower than Brian's speed. What was Brian's speed?
- The tourist
The tourist will cross a 5 km long section in 3 hours. Part of the journey goes at a speed of 0.8 m/s and the other part at a speed of 0.4 m/s. Find the length of the first and second part of the journey.
- Cooker spiral
A current of 4.4 A flow through the spiral of the electric cooker at a voltage of 220 V. What is the resistance of the spiral?
How long must a manganin wire with a diameter of 0.8 mm have to have a value of 10Ω?
- The train
The train starts for 2 min with an acceleration of 25 cm/s². What speed will he gain in this time and what path will he pass?
- The cyclist
The cyclist reaches a speed of 32 km/h in 3.4 seconds. What is its acceleration in m/s²?
- Angle ASB
On a circle with a radius of 10 cm and with a center S, the points A, B, C are given so that the central angle ASB is 60 degrees and the central angle ASC is 90 degrees. Find the length of the circle arc and the amount of AB and AC offsets.
- Serial resistors
In the circuit shown ( two resistiors R1 and R2 serial connected), the total resistance from A to B is 16 ohms. Find the resistance R2 and the current through the R1 = 12-Ohm resistor, if voltage between A and B is 10 V.
- Ice to boiling water
Calculate the heat needed to convert 5kg of ice with a temperature of -5°C to water with a temperature of 100°C. c (water) = 4200 J. Kg-1. kg-1, c (ice) = 2100 J. Kg-1. kg-1. the mass group heat of solidification of water is l = 334kJ/kg. Calculate the he
- Day trip
A group of tourists went on a day trip. For two hours they walked at a speed of 6 km/h, for another hour they climbed a steep hill at a speed of 2 km/h, spent an hour and a half at lunch, then in an hour they inspected the castle garden at a free step at
- The temperature 13
The temperature in Toronto at noon during a winter day measured 4°C. The temperature started dropping 2° every hour. Which inequality can be used to find the number of hours, x, after which the temperature will measure below -3°C?
What is the volume of a body that stretches a dynamometer in air, on which it is suspended by a force of 2.5 N, and if it is immersed in alcohol with a density of 800 kg/m ^ 3, does it tension the dynamometer with a force of 1.3 N?
- Lead melt
Find the heat needed to melt an object made of lead weighing 250g and an initial temperature of 35°C. Lead melts at 327°C at normal pressure. Mass heat capacity of lead c = 129 J/kg • K and mass latent heat of lead lt (t is the subscript) = 22.6 kJ/kg
- Above water surface
If we remove the stone from the water, we apply a force of 120N. How much force will we have to exert if we move the stone above the water surface? The density of the stone is 5000 kg/m ^ 3.
- What power
What power should the radiator have in a room 5x4 meters with a height of 3 meters? Hint: Calculate 35 watts per meter ^ 3 in case you need 22 degrees in the room but you need about 24 degrees in the bathroom. It's an old heating cheat, but it will defini
- Two cars
Two cars (trucks and passenger) drove simultaneously from two places 50 km away. If they go against each other, they will meet in 30 minutes. If they follow each other in the same direction, the car will catch up with the truck in 2.5 hours. What is the s
There is 5 l of water with a temperature of 20°C in the bucket. We add 3 liters of hot water. The resulting temperature will be 30°C. What was the temperature of the hot water?
Immerse a thermometer with a heat capacity of 2.0 J. K-1 in water weighing 67.0 grams. Before immersion in water, the thermometer showed a temperature of 17.8 degrees Celsius. After reaching equilibrium, the temperature is 32.4 degrees. What was the water
- Latent heat
How much heat is needed to take from 100 g of water at 20°C to cool to ice at -18°C? Mass heat capacity c (ice) = 21kJ/kg / °C; c (water) = 4.19 KJ/kg / °C and the mass group heat of solidification of water is l = 334kJ/kg
Fundamentals of Physics - practice problems. Examples for 9th grade.