Answer:
Power, P = 600 watts
Explanation:
It is given that,
Mass of sprinter, m = 54 kg
Speed, v = 10 m/s
Time taken, t = 3 s
We need to find the average power generated. The work done divided by time taken is called power generated by the sprinter i.e.

Work done is equal to the change in kinetic energy of the sprinter.


P = 900 watts
So, the average power generated by the sprinter is 900 watts. Hence, this is the required solution.
Answer:
(a) 
(b) 
Explanation:
Represent losing with L and winning with W.
So:
--- Given

Probability of winning would be:



The question illustrates binomial probability and will be solved using the following binomial expansion;

So:
Solving (a): Winning at least 1
We look at the above and we list out the terms where the powers of W is at least 1; i.e., 1,2,3 and 4
So, we have:

Substitute value for W and L


<em>Hence, the probability of her winning at least one is 0.7599</em>
Solving (a): Wining exactly 2
We look at the above and we list out the terms where the powers of W is exactly 2
So, we have:

Substitute value for W and L


<em>Hence, the probability of her winning exactly two is 0.2646</em>
The answer is c, positron.
Answer:
301.48 J/s
Explanation:
We are given;
Temperature of the sky dropping to −40∘C: T_o = -40°C = -40 + 273 = 233 K
Temperature of your skin and clothes: T = 30°C = 30 + 273 = 303 K
Body surface area of human body is around 2 m². But here only half of the body is facing the sky, Thus Area is: A = 2/2 = 1 m²
To solve this, we will use the equation for thermal heat transfer known as the Stefan bolt Mann equation.
ΔQ/Δt = εσA(T⁴ - (T_o)⁴)
Where;
ΔQ/Δt is the rate at which you body loses energy by radiation
ε is the emissivity of the human body with a value of 0.97
σ is Stefan boltzmann constant with a value of 5.67 X 10^(-8) W/m².K⁴
Thus;
ΔQ/Δt = 0.97 × 5.67 X 10^(-8) × 1(303⁴ - 233⁴)
ΔQ/Δt = 301.48 J/s