Answer:
10s
Explanation:
If it took Beatrice 25 seconds to complete the race
Distance = 100 meter
Beatrice speed = 100/25
= 4m/s
If Alice runs at a constant speed and crosses the finish line $5$ seconds, she must have completed the race in 20s (25 -5).
Her speed where constant
= 100/20
= 5 m/s
It would take Alice
= 50/5
= 10s
It would take Alice 10s to run $50$ meters.
I think The coastal areas were highly polluted
Explanation:
a. Net force is mass times acceleration (Newton's second law).
∑F = ma
∑F = (5.0 kg) (2.0 m/s²)
∑F = 10 N
b. The net force is the sum of the individual forces.
10 N = F − 5 N
F = 15 N
c. Friction force here is mgμ.
mgμ = 5 N
(5.0 kg) (10 m/s) μ = 5 N
μ = 0.1
Kinetic energy of pieces A and B are 2724 Joule and 5176 Joule respectively.
<h3>What is the relation between the masses of A and B?</h3>
Mass of piece B = Mb
- Velocities of pieces A and B are Va and Vb respectively.
- As per conservation of momentum,
Ma×Va = Mb×Vb
So, 1.9Mb × Va = Mb×Vb
=> 1.9Va = Vb
<h3>What are the kinetic energy of piece A and B?</h3>
- Expression of kinetic energy of piece A = 1/2 × Ma × Va²
- Kinetic energy of piece B = 1/2 × Mb × Vb²
- Total kinetic energy= 7900J
=>1/2 × Ma × Va² + 1/2 × Mb × Vb² = 7900
=> 1/2 × Ma × Va² + 1/2 × (Ma/1.9) × (1.9Va)² = 7900
=> 1/2 × Ma × Va² ×(1+1.9) = 7900 j
=> 1/2 × Ma × Va² = 7900/2.9 = 2724 Joule
- Kinetic energy of piece B = 7900 - 2724 = 5176 Joule
Thus, we can conclude that the kinetic energy of piece A and B are 2724 Joule and 5176 Joule respectively.
Learn more about the kinetic energy here:
brainly.com/question/25959744
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