Coals energy is affordable and it is easy to burn.
smartphones break due to forces acting on the material.
force causes material to deform.
material is often brittle and cracks due to a limit on hardness / electricity in screens.
newton's 2nd law states
force = DV / DT
to help phones we must slow down change in momentum to reduce the force
thus we must use some form of damping in the form of a case .
the case is typically able to deform and rubber is elastic converting the kinetic energy to heat as it deforms instead of transferring it through the screen.
therefore the change in velocity occurs over a longer time. therefore the impulse decreases
Answer:
a = - 1.987 × 10⁶ ft/s²
t = 6.84 × 10⁻⁴ s
Explanation:
v₀ = 910 ft/s
x = 5 in.
relation v = v₀ - k x
v = 0 as body comes to rest
0 = 900 - 5k/12
k = 2184 s⁻¹
acceleration

where
(A) a = -k × v
at v= 910 ft/s
a = - 1.987 × 10⁶ ft/s²
(B) at x = 3.9 in.
v = 910 - 3.9(2184)/12
v = 200.2 m/s




t = 6.84 × 10⁻⁴ s
Answer:
reference against doubt
Explanation:
exact standards of measurement are a reference point for situations in doubt , a line against which to test and observe.
Answer:
force×distance
Explanation:
work is the ability of an object to move a distance as a result of the force being applied