The sister catches up Jeff after 2 hours
Step-by-step explanation:
We can write Jeff's position and his sister position at time t using the following expressions:
- Jeff position:

where:
7 is the initial position of Jeff when his sister sarts chasing him
2.5 is Jeff's velocity (in miles/hour), so its position increases by 2.5 miles for each hour
t is the time measured in hours
- Sister position:

where
6 is the sister velocity (her position increases by 6 miles for every hour)
t is the time measured in hours
The sister catches up Jeff when the two positions are equal, so

And solving for t,

So, the sister catches Jeff after 2 hours.
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Answer:
C,. 3 3/4
Step-by-step explanation:
length times with times hight
1 1/4 x 1 1/2 x 2
convert everything to same denominator
1 1/4
1 2/4
1 4/4
solve
1 1/4 x 1 2/4 x 1 4/4
Answer:
The force is 12 N
Step-by-step explanation:
* Lets explain how to solve the problem
- Direct variation is a relationship between two variables that can
be expressed by an equation in which one variable is equal to a
constant times the other
- If y ∝ x , then y = kx , where k is the constant of variation
* Lets solve the problem
- The force acting on the object varies directly with the object's
acceleration
∵ The force is F in newtons and a is the acceleration is m/s²
∴ F ∝ a
∴ F = ka
- To find k substitute F and a by the initial values of them
∵ A force of 10 N acts on a certain object, the acceleration of the
object is 5 m/s²
∵ F = 10 N when a = 5 m/s²
∵ F = ka
∴ 10 = k(5)
- Divide both sides by 5
∴ K = 2
- Substitute the value of k in the equation
∴ F = 2a
- Lets find the force when the acceleration is 6 m/s²
∵ a = 6 m/s²
∴ F = 2(6) = 12
* The force is 12 N
By using simple rule of three, a period of 9.5 years on Venus is equivalent to 2134.65 terrestrial days.
<h3>How many terrestrial days are equivalent time in Venus?</h3>
One year on Earth is equivalent to 365.3 days and one year on Venus is equivalent to 224.7 days, the equivalent terrestrial time of 9.5 years on Venus is found by simple rule of three:
x = 9.5 yr × (224.7 days / 1 yr)
x = 2134.65 days
A period of 9.5 years on Venus is equivalent to 2134.65 terrestrial days.
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