Answer:
v = 22.54 mph.
Explanation:
Given that,
Distance moved, d = 200 m
Time, t = 19.8 s
We need to find the runner's average speed.
We know that,
1 mile = 1609.34 m
200 m = 0.124 miles
19.8 seconds = 0.0055 h
So,
Speed = distance/time

So, the runner's average speed is 22.54 mph.
Potential energy is defined by formula

here
m = mass
g = acceleration due to gravity
h = height
Now here two different stones are located at same height
while mass of stone A is twice that of stone B
so here we can say potential energy of A is

Similarly potential energy of B is

now if we take the ratio of two energy

so we can say potential energy of stone A is two times the potential energy of B
Explanation:
6. Converge or come together
7. convex
Answer:
5.5g of ice melts when a 50g chunk of iron at 80°C is dropped into a cavity
Explanation:
The concept to solve this problem is given by Energy Transferred, the equation is given by,

Where,
Q= Energy transferred
m = mass of water
c = specific heat capacity
Temperature change (K or °C)
Replacing the values where mass is 50g and temperature is 80°C to 0°C we have,



Then we can calculate the heat absorbed by m grams of ice at 0°C, then

How Q_1=Q_2, so



Then 5.5g of ice melts when a 50g chunk of iron at 80°C is dropped into a cavity
Normal force, friction force, gravitational force