EC_1 + EP_1 = EC2 + EP_2
EC_2 = 0
EC_2 = EP_1 - EP_2
EC_2 = mg(H_1 - H_2) = 0.20 kg * 9.8 m/s^2 * (3.25 m - 1.5m) = 3.43 J
Answer:
Explanation:
Using the first law of thermodynamics:
Where 
is the change in the internal energy of the system, in this case 
, 
is the heat tranferred, and 
is the work, 
with a negative sign since the work is done by the system.
From the previous equation we solve for heat, because it is the unknown variable in this problem
And replacing the known values:
The negative sign shows us that the heat is tranferred from the system into the surroundings.
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.
