Answer:
7.6 s
Explanation:
Considering kinematics formula for final velocity as

Where v and u are final and initial velocities, a is acceleration and s is distance moved.
Making v the subject then

Substituting 8.8 m/s for u, 138 m for s and 2.45 m/s2 for a then

Also, v=u+at and making t the subject of the formula

Substituting 27.45 m/s for v, 8.8 m/s for u and 2.45 m/s for a then

Therefore, it needs 7.6 seconds to travel
Answer:
$893
Explanation: the complete question should be
The clothes washer in your house consumes 470 kWh of energy per year. Price of the washer is $360 and the lifetime of the washer is 10 yrs. Energy price in your city is 9 cents per kWh. What is the lifecycle cost of the clothes washer? (assume a maintenance cost of $11 per year)
SOLUTION
Given:
The clothes washe power consumption (PC) is 470 kWh
Price of the washer (P) is $360
lifetime of the washer (L) is 10 yrs
Energy price in the city (E) is 9 cents per kWh (Covert to $ by dividing 100)
maintenance cost (M) is $11 per year
Lifecycle cost = P + (PC × L × E) +M + L
Lifecycle cost = $360 + (470kWh × 10years × 9cents/100) + ($11 × 10years)
=$893
Answer:
it's because some versions have more steps and others have less
The point of contact the path difference is zero but one of the interfering ray is reflected so the effective path difference becomes λ/2 thus the condition of minimum intensity is created in the center.