Answer:
a) 70,560 J
b) 88.2 N/m
Explanation:
The spring potential will equal the change in gravity potential
PS = PE = mgh = 80(9.8)(100 - 10) = 70,560 J
PS = ½kx²
k = 2PS/x² = 2(70560)/(100 - 50 - 10)² = 88.2 N/m
Answer:
a) σa−σb−σc−σd=0
Explanation:
The parallel plate capacitor is the one in which two metal plates are connected in parallel with some distancing among them. The electric field from both plates is denoted by E = σ / 2ϵ0. The σ is the charge density. The Electric field in plate I will vanish when the surface charge of σa is positive and rest of the charges are negative. The correct option is a.
Answer:
B. Decrease the plane’s speed and height
Explanation:
Decrease in speed of plane:
When the speed of the plane is decreased then initial velocity of the package will be lesser. As a result, final velocity will also be lesser because in this case final velocity depends upon the initial velocity.
Decrease in height:
According to law of conservation of energy:
Loss in potential energy = Gain in Kinetic energy
mgh = ½ mV^2
It means with the decrease in height less potential energy will be converted to kinetic energy. As package has constant mass so it will gain less velocity.
Answer:
640 J
Explanation:
ΔKE = KE − KE₀
ΔKE = ½ mv² − ½ mv₀²
ΔKE = ½ m (v² − v₀²)
ΔKE = ½ (80 kg) ((5 m/s)² − (3 m/s)²)
ΔKE = 640 J
Her kinetic energy increases by 640 J, so she does 640 J of work.
A graph of real speed can have a section that's as steep as you want,
but it can never be a perfectly vertical section.
Any vertical line on a graph, even it it's only a tiny tiny section, means
that at that moment in time, the speed had many different values.
It also means that the speed took no time to change from one value to
another, and THAT would mean infinite acceleration.
