Explanation:
time spent to run from house to school=100/5=20s
time spent to return from school=100/10=10s
average velocity=200m/(10+20)
Answer:
215000kgm/s
Explanation:
Given parameters:
Mass of the moving body = 5000kg
Velocity = 43m/s
Unknown:
Momentum = ?
Solution:
The momentum of a body is the amount of motion a body possess.
It is mathematically expressed as:
Momentum = mass x velocity
Now:
Momentum = 5000 x 43 = 215000kgm/s
Answer:
b. 9.5°C
Explanation:
= Mass of ice = 50 g
= Initial temperature of water and Aluminum = 30°C
= Latent heat of fusion = 
= Mass of water = 200 g
= Specific heat of water = 4186 J/kg⋅°C
= Mass of Aluminum = 80 g
= Specific heat of Aluminum = 900 J/kg⋅°C
The equation of the system's heat exchange is given by
The final equilibrium temperature is 9.50022°C
Answer:
B)
Explanation:
The value the scale shows is the reaction force to the normal force (they are equal by Newton's 3rd Law) that the scale exerts on Eric.
The forces on Eric are his weight (downward) and this normal force (upward), so we can write the net force over him as (also using Newton's 2nd Law):
which means
and for our values this is:
As an object falls from rest, its gravitational energy is converted to kinetic energy
G.P.E = K.E = mgh
K.E = (80 Kg)(9.8 m/s²)(30 m)
K.E. = 23,520 J
