Passengers in a high-flying jumbo jet feel their normal weight in flight, while
ID: 1409907 • Letter: P
Question
Passengers in a high-flying jumbo jet feel their normal weight in flight, while passengers in an orbiting space vehicle do not, because passengers in the space vehicle are A) Without support forces. B) Beyond the main pull of Earth's gravity C) above Earth's atmosphere D) all of the above E) None of the above. 2) A feather and a coin dropped in a vaccum fall with equal A) forces due to gravity B) accelrations C) Kinetic energies. D) None of these 3) A 5000-Kg frieght car moving at 2 m/s colletction with a 10,000-Kg frieght car at rest. They couple upon collision and move away at A) 1 m/s B) 2 m/s C) 2/3 m/s. D) 1/3 m/s 4) A weight watcher who normally wieghs 400 N stands on top of a very tall ladder so she is one Earth radius above Earth's surface. How much is her wieght there? A) 200 N B) 0 C) 400 N E) none of the above 5) A mack truck and a volkswagen traveling at the same speed have a head - on collision The vehicle that undergoes the greatest cfhange in velocity chane in velocity will be the A) Mack Truck B) Same for both. C) Volkswagen 6) If an all-electric car has kinetic energy, then it also must have A) acceleration B) force C) momentum D) impulse E) None of the aboveExplanation / Answer
(1)
Correct Option :- (E)
(2)
In Vaccum, they will have equal acceleration !!
Correct Option :- (B)
(3)
Using Momentum Conservation,
m1*v1 + m2*v2 = (m1+m2) * v
5000 * 2 + 10000 * 0 = (5000 + 10000) * v
v = 2/3 m/s
Correct Option :- (C)
(4)
Gravitational force varies as 1/r^2 where r is the distance from the center of the earth
At the surface of the earth, she is 1 earth radius from the center.
At the new height, she is 2 earth radius from the center.
So, her distance from the center of the earth has doubled and her weight will change by a factor of 1/2^2 = 1/4
her new weight is 1/4 of her prior weight
= 1/4 x 400N
= 100 N
Correct Option :- (D)
(5)
As Mass of car < Mass of truck
Maximum change in Velocity will be for Volkswagen,
Correct Option :- (C)
(6)
K.E = 1/2*m*v^2
This can be written as,
K.E = 1/2 * (m*v)^2 / m
K.E = 1/2 * P^2/m = P^2/(2*m)
Where p is momentum,
Correct Option :- (C)