Answer:
1703.24J
Explanation:
Given parameters:
Mass of brick = 7.9kg
Height of building = 22m
Unknown:
Potential energy of the brick = ?
Solution:
The potential energy of a body is the energy at rest of the body. Mathematically;
P.E = mgh
m is the mass of the brick
g is the acceleration due to gravity
h is the height of the building
Insert the given parameters and solve;
P.E = 7.9 x 9.8 x 22 = 1703.24J
Answer:
Option B, Some of the cars' kinetic energy was converted to sound and heat energy.
Explanation:
In an elastic collision, no energy is lost during and after collision. Thus, it can be said that in an elastic collision both momentum and kinetic energy remains conserved.
While in non-elastic collision, kinetic energy of the system is lost. However, the momentum of the system is conserved. Generally, during and after collision some of the kinetic energy is lost as thermal energy, sound energy etc.
Hence, option B is correct
Answer:
7.7 km 26°
Explanation:
The total x component is:
x = 2.5 cos(35°) + 5.2 cos(22°) = 6.87
The total y component is:
y = 2.5 sin(35°) + 5.2 sin(22°) = 3.38
The magnitude is:
d = √(x² + y²)
d = 7.7 km
The direction is:
θ = atan(y/x)
θ = 26°
××
×
50N is your force and the acceleration is -9.8m/s^2 due to gravity.
So, you just plug that in.
BUT you know that mass cannot be negative, so you just disregard the negative sign and the mass of the rock is 5.102 grams.
