<em>"A concave lens is thinner at the center than it is at the edges."</em>
If this isn't on the list of choices, that's tough. We can't help you choose the best one if we don't know what any of them is.
Explanation:
Given that,
Rate of cooling of air
Initial temperature= 80°C
Final temperature = 5°C
We need to calculate
Using newton's law of cooling


Where, 
Here,
= 25°C (surrounding temperature)
dt = 1 minute

Put the value into the formula



Hence, This is the required answer.
Answer:
b
Explanation:
n = m(g +a)
n= normal force (N)
m=mass (kg)
g=acceleration of gravity
a= acceleration of elevator
rearrange:
a= n/m - g
a= (810 N/73 kg) - 9.8 m/s ^2
a= 1.3 m/s ^2 up
and the acceleration is upwards bc her weight is less than the scale reading
Answer:
Lion Average speed:60 km/h
Explanation:
Answer:
Average speed = 5 m/s
Explanation:
Given the following data;
Distance = 100m
Time = 20 secs
To find the average speed;
Speed = distance/time
Substituting into the formula, we have;
Speed = 100/20
Speed = 5m/s
Therefore, Elsa's average speed is 5 meters per seconds.