Answer:
1. 610,000 lb ft
2. 490 J
Explanation:
1. First, convert mi/hr to ft/s:
100 mi/hr × (5280 ft / mi) × (1 hr / 3600 s) = 146.67 ft/s
Now find the kinetic energy:
KE = ½ mv²
KE = ½ (1825 lb / 32.2 ft/s²) (146.67 ft/s)²
KE = 610,000 lb ft
2. KE = ½ mv²
KE = ½ (5 kg) (14 m/s)²
KE = 490 J
I think there was momentum conserved
Explanation: I took the test
Option (a) is correct.
Falling objects accelerate as they approach the ground.This is because of the force of gravity acting on the falling objects. so the velocity of these objects increases continuously as they approach the ground. the acceleration acting on the falling objects is a constant ( close to the surface of earth) and is called as acceleration due to gravity denoted by g. value of g=9.8 m/s².
Answer:
Explanation:
|F-->1| = E-->1 x charge on proton
= 300 x 1.6 x 10⁻¹⁹
Magnitude of electric force on proton
|F-->1| = 480 x 10⁻¹⁹ N .
Inside lithium nucleus , there are three protons so charge on it
= 3 x 1.6 x 10⁻¹⁹ = 4.8 x 10⁻¹⁹ C .
Magnitude of electric force on lithium nucleus
|F-->Li| = E-->1 x charge on lithium nucleus
= 300 x 4.8 x 10⁻¹⁹
= 1440 x 10⁻¹⁹ N .
Electron has same charge as that possessed by proton so charge on electron = 1.6 x 10⁻¹⁹ C
Magnitude of force on electron
|F-->1| = E-->1 x charge on electron
= 300 x 1.6 x 10⁻¹⁹
= 480 x 10⁻¹⁹ N .
Answer:
ΔT = 302 °c
Explanation:
mass (m) = 4.6 g = 0.0046 kg
velocity (v) = 278 m/s
specific heat of lead (c) = 128 J/kg. °c
kinetic energy = 0.5 mx 
kinetic energy = 0.5 x 0.0046 x 
kinetic energy = 177.8 J
since all the kinetic energy is converted to thermal energy,
kinetic energy = thermal energy (E) = 177.8 J
thermal energy = m x c x ΔT
where ΔT is the temperature change
177.8 = 0.0046 x 128 x ΔT
ΔT = 177.8 / 0.59
ΔT = 302 °c
