Answer:
Explanation:
Let t represent the time for Tina to catch David.
Hence, considering the equation of linear motion S = ut + 1/2at^2..... 1
For David u = 28.0 m/s where 'a' is set to nought
S = ut
S = 28t.......2
For Tina consider equation 1
Where acceleration = 2.90m/s^2 and u is set at nought
S = 1/2×2.90 m/s×t^2.......3
Equate 2 and 3
28t = 1.45t^2
Divide through by t
28 = 1.45t
t = 28/1.45
t = 19.31seconds
Now put the value of t into equation 3
S = 1/2×2.90 m/s×t^2.......3
= 1.45×20×20
= 580m
Tina must have driven 580meters before passing David
Considering the equation of linear motion : V^2 = U^2+2as
Where u is set at nought
V^2 = 2as
V^2 = 2×2.9×580
V^2 = 3364
V = √3364
V = 58m/s
Her speed will be 58m/s
Answer:
The correct answer is = 1.6
Explanation:
Density of water = 1000kg/m³ = d₁
Mass of brick = 4kg = m
Density of brick = 2.5 g/cm³ = 2.5 × 1000 =2500 kg/m³ = d₂
Volume of brick = m/d₂ = 4/2500 =16/10000 = 0.0016 L = v
Buoyant Force = v × d₁ × g (g= acceleration due to gravity =9.8m/s²)
= 0.0016 × 1000 × 9.8 = 15.68 Newtons
By the Archimedes' Principle, the buoyant force is equal to the weight of the liquid displaced by an object.
Weight of the water displaced=Buoyant Force
=Mass of water displaced × g,
as weight = mass × acceleration due to gravity
15.68= mass of brick × 9.8
15.68/9.8 =Mass of water displaced
1.6 kg = Mass of water displaced
Answer:
180,000
Explanation:
Frequency is a quantity that is measured in Hertz [Hz] and it represents the number of rotations per second.
A motor with a frequency of 50 Hz will rotate 50 times per second.
Since we don't want to know how many times it rotates per second, but per hour. The first step is to find how many seconds there are in an hour and then multiply that amount by 50.
Seconds in an hour:
there are 60 seconds per minute, and 60 minutes per hour, thus there are
60*60 = <u>3,600 seconds in an hour</u>
We know that the motor will rotate 50 times per second so to find the number of rotations in 1 hour = 3,600 seconds we multiply:
50*3,600 = 180,000 rotations
Main sequence stars are characterised by the source of their energy.They are all undergoing fusion of hydrogen into helium within their cores. The mass of the star is the main element for such process or phenomenon to take place for it is a determinant of both the rate at which they perform the said activity and the amount of fuel available.
To answer the question, the lower mass limit for a main sequence star is about 0.08. If the mass of a main sequence star is lower than the above-mentioned value, there would be a deficit or insufficiency of gravitational force to generate a standard temperature for hydrogen core fusion to take place and the underdeveloped star would form into a brown dwarf instead.
Answer:
b. Relates the electric field at points on a closed surface to the net charge enclosed by that surface
Explanation:
Gauss's law states that the flux of certain fields through a closed surface is proportional to the magnitude of the sources of that field within the same surface. The electric flux expresses the measure of the electric field that crosses a certain surface. Therefore, the electric field on a closed surface is proportional to the net charge enclosed by that surface.
