Threshhold frequency is defined as the minimum light frequency necessary to start photo-electric emission from the surface. This frequency is just effecient enough to emit electrons without any additional force or energy. this minimum frequency creates the necessary result that is sought by the person. The photo electric emission for certain metals can occir with threshhold frequency. The importance of this threshhold frequency lies in the fact that this has been used to create numerous instruments like amplifiers for use of people.
Using Newton's second law;
F = ma, where m = mass, a = acceleration or deceleration
a = Δv/t = (v-u)/t, but v= 0, u = 10 m/s, t = 1.
Then,
a = (0-10)1 = -10 m/s^2
Substituting;
F = ma = 10*-10 = -100 N
The mattress exerts 100 N to stop the ball.
Answer:
(a) 2.33 A
(b) 15.075 V
Explanation:
From the question,
The total resistance (Rt) = R1+R2 = 3.85+6.47
R(t) = 10.32 ohms.
Applying ohm's law,
V = IR(t)..........equation 1
Where V = Emf of the battery, I = current flowing through the circuit, R(t) = combined resistance of both resistors.
Note: Since both resistors are connected in series, the current flowing through them is the same.
Therefore,
I = V/R(t)............. Equation 2
Given: V = 24 V, R(t) = 10.32 ohms
Substitute these values into equation 2
I = 24/10.32
I = 2.33 A.
Hence the current through R1 = 2.33 A.
V2 = IR2.............. Equation 3
V2 = 2.33(6.47)
V2 = 15.075 V
This problem is a piece o' cake, IF you know the formulas for both kinetic energy and momentum. So here they are:
Kinetic energy = (1/2) · (mass) · (speed²)
Momentum = (mass) · (speed)
So, now ... We know that
==> mass = 15 kg, and
==> kinetic energy = 30 Joules
Take those pieces of info and pluggum into the formula for kinetic energy:
Kinetic energy = (1/2) · (mass) · (speed²)
30 Joules = (1/2) · (15 kg) · (speed²)
60 Joules = (15 kg) · (speed²)
4 m²/s² = speed²
Speed = 2 m/s
THAT's all you need ! Now you can find momentum:
Momentum = (mass) · (speed)
Momentum = (15 kg) · (2 m/s)
<em>Momentum = 30 kg·m/s</em>
<em>(Notice that in this problem, although their units are different, the magnitude of the KE is equal to the magnitude of the momentum. When I saw this, I wondered whether that's always true. So I did a little more work, and I found out that it isn't ... it's a coincidence that's true for this problem and some others, but it's usually not true.)</em>
Answer:
114.32195122 but Round your answer to three significant figures.) is 114
Explanation:
Just took the test
