Answer:
Explanation:
As we know that bullet + pendulum system will move to the height of 0.650 m above the initial position
so here we can use energy conservation to find the speed just after the bullet hit the block
Now we can use momentum conservation to find the initial speed of the bullet
When moving upwards, the normal force from the weighing scale on the person increases so the weight appears to increase. The opposite holds true when the elevator goes downwards.
Answer:
C 3.33 Ω
Explanation:
From the equation given 1 / Rtot = 1/10 + 1/5 = 3/10
then Rtot = 10/3 = 3.33 Ω
As an aside:
When there are only two resistors in parallel, the equivalent R is
= R1*R2 / (R1 + R2) = 10*5 / (10+5) = 50 / 15 = 3.33 Ω
Answer:
The velocity of the train is 82.8 km/h
Explanation:
The equation for the position of the train and the car is as follows:
x = x0 + v · t
Where:
x = position at time "t".
x0 = initial position.
v = velocity.
t = time.
First, let´s calculate the distance traveled by the car in 60 s (1/60 h). Let´s place the origin of the frame of reference at the front of the train when it starts to pass the car so that the initial position of the car is 0 (x0 = 0 m):
x = 0 m + 72 km/h · (1/60) h
x = 1.2 km.
Then, if the whole train passes the car at that time, the position of the front of the train at that time will be 1.2 km + 0.18 km = 1.38 km.
Then using the equation of position we can obtain the velocity:
x = x0 + v · t
1.38 km = 0 m + v · (1/60) h
1.38 km / (1/60) h = v
v = 82.8 km/h
The velocity of the train is 82,8 km/h
The same result could be obtained using the rear of the train. You only have to identify where the rear is at t = 0 and where it is at t = 60 s.
Try it!
