Linear Motion & Force
Heating Processes
Ionising Radiation
Random Science
Electrical Circuits
Waves
100
A car accelerates uniformly from rest to a speed of 20 m s-1 in 10 seconds. What is the car's acceleration?
20 m s-2
100
Convert 550C to K.
TK = 328 K
100
What is the half-life of this substance?
2 days
100
What is the most abundant gas in Earth's atmosphere?
The most abundant gas in Earth's atmosphere is nitrogen, making up about 78% of the air we breathe.
100
What is the total resistance across the simple circuit?
Rt = 15 + 5 + 20 = 40 Ohms
100
Identify the wavelength.
4 cm
200
A 5 kg object is acted upon by a force of 15 N. What is the acceleration of the object?
3 m s-2
200
How much energy is required to raise the temperature of 2 kg of water from 20°C to 50°C? (The specific heat capacity of water is 4.18 x 103 J kg-1 K-1)
Q = 252 000 J
200
How many half-lives would carbon-14 have to undergo to have 12.5% remaining of the original amount?
3 half-lives
200
What part of the human cell is responsible for generating most of the cell's energy?
The part of the human cell responsible for generating most of the cell's energy is the mitochondrion (plural: mitochondria). It is often referred to as the "powerhouse of the cell" because it produces ATP (adenosine triphosphate), which is the cell's main energy currency.
200
A resistor has a current of 3 A flowing through it when connected to a 12 V battery. What is the resistance of the resistor?
4 Ohms
200
Henry points a laser at a mirror at an angle of 62o. What is the angle of reflection?
angle of incidence = angle of reflection
62o
300
A car accelerates uniformly from rest to a speed of 30 m s-1 in 8 seconds. Calculate the acceleration and the distance covered during this time.
a = 3.75 m s-2
s = 120 m
300
A heater consumes 1,000 J of electrical energy and produces 700 J of heat energy. What is the efficiency of the heater? Express your answer as a percentage.
70%
300
A radioactive substance has a half-life of 8 hours. If you start with 80 grams of the substance, how much will remain after 24 hours?
N = 10 g
300
Which element has the highest melting point of all the elements on the periodic table?
The element with the highest melting point on the periodic table is tungsten (W). Its melting point is approximately 3,422°C (6,192°F).
300
In a simple electrical circuit, you have three resistors: Resistor A (5 Ω), Resistor B (10 Ω), and Resistor C (15 Ω). If the resistors are connected in parallel, calculate the total resistance of the circuit.
300
Calculate the frequency.
f = 1.11 Hz
400
A ball is thrown vertically upward with an initial speed of 20 m/s. Calculate the maximum height it reaches.
s = 20.4 m
400
How much energy is needed to melt 0.5 kg of ice at 0°C? (The specific latent heat of fusion for ice is 3.34 x 105 J kg-1.
Q = 167 000 J
400
A substance decreases by 70% of its original radioactive material over 8000 years. Find the half-life.
~ 4606 years
400
What is the name of the scientist who developed the theory of general relativity?
Albert Einstein
400
A device uses 240 W of power when connected to a 120 V source. If the device operates for 5 minutes, how much charge flows through the device?
600 C
400
A laser beam with an initial intensity of I0 = 500 W/m2 is directed through a filter that reduces the intensity by 40%. Calculate the intensity of the laser beam after it has passed through the filter.
I = 300 W/m2
500
A train traveling at 30 m s-1 begins to decelerate at a constant rate of 2 m s-2. How long will it take for the train to come to a stop, and how far will it travel during this time?
t = 15 s
s = 225 m
500
A 1.5 kg block of aluminium at 100°C is placed in 2 kg of water at 20°C. What will be the final equilibrium temperature of the system? Assume no heat loss to the surroundings, the specific heat capacity of aluminium is 900 J kg-1 K-1, and the specific heat capacity of water is 4.18 x 103 J kg-1 K-1.
Tf = 31.1oC
500
A sample initially contains 4.5×1012 atoms of thorium-234, a radioactive isotope with a half-life of 24.1 days. Estimate the time required for the sample to contain only 50,000 atoms of thorium-234.
~ 637 days
500
In genetics, what term describes the observable physical or biochemical characteristics of an organism as determined by both genetic makeup and environmental influences?
Phenotype
500
A heater has a current of 8 A and operates on a 250 V supply. How long does it take for the heater to do 180,000 joules of work?
90 seconds
500
A beam of light passes from water (refractive index n1 = 1.33) into a medium with a refractive index of n2 = 1.50. If the angle of incidence in the water is 30°, calculate the angle of refraction in the second medium.