Answer:
W = 1418.9 J = 1.418 KJ
Explanation:
In order to find the work done by the pull force applied by Karla, we need to can use the formula of work done. This formula tells us that work done on a body is the product of the distance covered by the object with the component of force applied in the direction of that displacement:
W = F.d
W = Fd Cosθ
where,
W = Work Done = ?
F = Force = 151 N
d = distance covered = 10 m
θ = Angle with horizontal = 20°
Therefore,
W = (151 N)(10 m) Cos 20°
<u>W = 1418.9 J = 1.418 KJ</u>
Explanation:
Watts are defined as 1 Watt = 1 Joule per second (1W = 1 J/s)
which means that 1 kW = 1000 J/s. A Watt is the amount of energy (in Joules) that an electrical device (such as a light) is burning per second that it's running.
Speed can never be negative because it does not depend in which direction the car moves whereas, velocity will change if a car turns from due North to East.
Quantities which can be described only by their magnitudes are called scalars and those which are described by both, magnitude and direction are vectors
Halflife is the time taken by a radioactive substance by half its original mass. In this case the half life of the substance is 3 hours.
Therefore; New mass = Original mass × (1/2)^n where n is the number of half lives. In this case, the half life is 3 hours and therefore; the number of half lives in 6 hours will be two.
= if the original mass is 100%
new mass = 100 × (1/2)^2
= 100 × 1/4 = 25%
The remaining mass will be 1/4 of the original mass, meaning a fraction of 3/4 of the initial mass will have decayed.
Thus; the answer is 3/4
