Answer:
The speed with which just after he grabs her is 2.68 m/s.
Explanation:
Given that,
Mass of Erica, m = 38 m/s
Mass of Danny, m' = 46 kg
Erica reaches the high point of her bounce, Danny is moving upward past her at 4.9 m/s. At this moment, the initial speed of Erica will be 0. The momentum will remain conserved. Using the conservation of linear momentum as :
So, the speed with which just after he grabs her is 2.68 m/s. Hence, this is the required solution.
Answer:
Maximum weight that can be lifted = 18,000 N
Explanation:
Given:
Cross-sectional area of input (A1) = 0.004 m²
Cross-sectional area of the output (A2) = 1.2 m
²
Force (F) = 60 N
Computation:
Pressure on input piston (P1) = F / A1
Assume,
Maximum weight lifted by piston = W
Pressure on output piston (P2) = W / A2
We, know that
P1 = P2
[F / A1] = [W / A2]
[60 / 0.004] = [W / 1.2]
150,00 = W / 1.2
Weight = 18,000 N
Maximum weight that can be lifted = 18,000 N
Let's see: frequency of cellular phone waves (GSM phones) is (800-1900 MHz). If we look at the table of the electromagnetic spectrum, we can see that this range is contained within the frequencies of the microwaves, which include waves in the range 300 MHz-300 GHz.
So, summarizing, the correct answer is "microwaves".
It is a stretch of the atmosphere ranging from the upper mesosphere to the lower parts of the thermosphere. It’s useful to us in radio communication.
