False. Not all contraceptives prevent STIs.
Contraceptives are items used or taken to prevent conception. These are birth control pill, patch, ring, IUD, birth control shots, and condoms. Among these contraceptives, condoms are the only type of birth control that prevents STIs or Sexually Transmitted Infections.
Answer:
When we burn wood we are releasing solar energy, in the form of heat, that has been stored in the wood as chemical energy. The process of photosynthesis converted solar energy, water and carbon dioxide into oxygen and the organic molecules that form the wood, half the weight of which is carbon.
Explanation:
Answer:
1.06 secs
Explanation:
Initial speed of sled, u = 8.4 m/s
Final speed of sled, v = 5.8 m/s
Coefficient of kinetic friction, μ = 0.25
Using the impulse momentum theory, we know that the impulse applied to the sled is equal to change in momentum of the sled:
FΔt = mv - mu
where m = mass of the object
Δt = time interval
F = force applied
The force applied on the sled is the frictional force, which is given as:
F = -μmg
where g = acceleration due to gravity
Therefore:
-μmgΔt = mv - mu
-μmgΔt = m(v - u)
-μgΔt = v - u
Making Δt subject of formula:
Δt = (v - u) / -μg
Δt = (5.8 - 8.4) / (-0.25 * 9.8)
Δt = -2.6/ -2.45
Δt = 1.06 secs
It took the sled 1.06 secs to travel from A to B.
Answer:
a) 
b) 
c) 
Explanation:
From the exercise we know the initial velocity of the projectile and its initial height
To find what time does it take to reach maximum height we need to find how high will it go
b) We can calculate its initial height using the following formula
Knowing that its velocity is zero at its maximum height
So, the projectile goes 1024 ft high
a) From the equation of height we calculate how long does it take to reach maximum point
Solving the quadratic equation
So, the projectile reach maximum point at t=2s
c) We can calculate the final velocity by using the following formula:
Since the projectile is going down the velocity at the instant it reaches the ground is:
Electroreception is limited to aquatic environments because on here is the resistivity of the medium is low enough for electric currents to be generated as the result of electric fields of biological origin. In air, the resistivity of the environment is so high that electric fields from biological sources do not generate a significant electric current. Electroreceptor are found in a number of species of fish, and in at least one species of mammal, the Duck-Billed platypus.
