It takes you 9.5 minutes to walk with an average velocity of 1.2 m/s to the north from the bus stop to museum entrance. What is your displacement?
Answer=5415m
If you travel along the straight line than the displacement is equal to the traveled distance.
s=vt
where v=1.2 m/s and t= 9.5 minutes
9.5(60s)=570s
s=9.5(570)=5415m
F=ma
Extra 100 points: F= change in p over change in t
change in momentum, Δp, with the corresponding change in time, Δt
An airliner reaches its takeoff speed of 163 mph in 36.2 s. What is the magnitude of its average acceleration.
Answer: What is 2 m/s^2
163 mph = 0.447*163 m/s = 72.9 m/s. The traveled time is 36.2 s.
Then the average acceleration is
a=72.9/36.2
=2 m/s^2
An object is launched at a velocity of 20 m/s in a direction making an angle of 25° upward with the horizontal.
Answer= 3.64 meters
maximum height y (0.86) = 20 sin(25°)(0.86) - (1/2) (9.8) (0.86) 2 = 3.64 meters
Δp=F(Δt)
Current flowing into a node (or a junction) must be equal to current flowing out of it
A rock is thrown straight upward off the edge of a balcony that is 5 m above the ground. The rock rises 10 m, then falls all the way down to the ground below the balcony. What is the rock's displacement?
Displacement deals only with the initial and final positions of the rock. The rock's initial position is the balcony, and its final position is the ground 5 m below. So, the rock's displacement is 5 m downward.
A ball is kicked at an angle of 35° with the ground. What is the time for the ball to reach the target?
t = x / V cos(35°) = 2.0 s
a=Δv/Δt
An athlete runs exactly once around a circular track with a total length of 500 m. Find the runner's displacement for the race.
Since the athlete runs exactly once around the circular track, that means that he/she finishes at the same point where he/she started, meaning the initial and final positions are the same.
Options: x or y
A car drives in a straight line at a constant speed of 60 miles per hour for 5 seconds. Find its acceleration.
Since the car's velocity is constant, there is no acceleration. So, a = 0.
v^2=u^2+2as
s=1/2(u+v)t
s=ut+1/2at^2
The net electromotive force around a closed circuit loop is equal to the sum of potential drops around the loop