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>
Answer:
<u><em>375 J</em></u>
Explanation:
<u><em>Total energy</em></u> = 750 J
<u><em>Efficiency</em></u> = 50%
<u><em>Wasted energy</em></u> = 50% [100% - 50%]
<u><em>Amount of wasted energy</em></u>
= 750 x 50%
= 750 x 0.5
= 375 J
The gravitational potential energy of the brick is 25.6 J
Explanation:
The gravitational potential energy of an object is the energy possessed by the object due to its position in a gravitational field.
Near the surface of a planet, the gravitational potential energy is given by

where
m is the mass of the object
g is the strength of the gravitational field
h is the height of the object relative to the ground
For the brick in this problem, we have:
m = 8 kg is its mass
g = 1.6 N/kg is the strenght of the gravitational field on the moon
h = 2 m is the height above the ground
Substituting, we find:

Learn more about potential energy:
brainly.com/question/1198647
brainly.com/question/10770261
#LearnwithBrainly
I believe the answer would be Light rays are reflected by mirrors