Answer:
(c) 97 dB sound intensity level
Explanation:
We have given the intensity of the loud car horn
We know that
Now the sound intensity level is given by , which is nearly equal to 97
So the sound intensity level will be 97 dB
So option (c) will be the correct option
Answer:
11405Volt
Explanation:
To solve this problem it is necessary to use the concept related to induced voltage or electromotive force measured in volts. Through this force it is possible to maintain a potential difference between two points in an open circuit or to produce an electric current in a closed circuit.
The equation that allows the calculation of this voltage is given by,
Where
B = Magnetic field
A= Area
N = Number of loops
= Angular velocity
Our values previously given are:
We need convert the angular velocity to international system, then
Applying the equation for emf, we replace the values and we will obtain the value.
Answer:
a) 4.45 m/s
b) 0.9 seconds
Explanation:
t = Time taken
u = Initial velocity
v = Final velocity
s = Displacement
a = Acceleration due to gravity = 9.81 m/s²
a) The vertical speed when the player leaves the ground is 4.45 m/s
Time taken to reach the maximum height is 0.45 seconds
Time taken to reach the ground from the maximum height is 0.45 seconds
b) Time the player stayed in the air is 0.45+0.45 = 0.9 seconds
b. how long does it take dave to cross the river?
c. how far downstream is dave’s landing point?
d. how long would it take dave to cross the river if there were no current?
a) Let's call x the direction parallel to the river and y the direction perpendicular to the river.
Dave's velocity of 4.0 m/s corresponds to the velocity along y (across the river), while 6.0 m/s corresponds to the velocity of the boat along x. Therefore, the drection of Dave's boat is given by:
relative to the direction of the river.
b) The distance Dave has to travel it S=360 m, along the y direction. Since the velocity along y is constant (4.0 m/s), this is a uniform motion, so the time taken to cross the river is given by
c) The boat takes 90 s in total to cross the river. The displacement along the y-direction, during this time, is 360 m. The displacement along the x-direction is
so, Dave's landing point is 540 m downstream.
d) If there were no current, Dave would still take 90 seconds to cross the river, because its velocity on the y-axis (4.0 m/s) does not change, so the problem would be solved exactly as done at point b).
Answer:
Explanation:
Hello.
In this case, since the normal force is opposite to the total present weight, we can compute it by considering the mass of the classmate with the gravity to compute its weight, and the weight of the table:
Best regards.
Answer:
Both cars travel at < 10 , 4 > m/s
Explanation:
Conservation of Linear Momentum
The total momentum of a system of particles of masses m1 and m2 traveling at velocities v1 and v2 (vectors) is given by
When the particles collide, their velocities change to v1' and v2' while their masses remain unaltered. The total momentum in the final condition is
We know the collision is perfectly inelastic, which means both cars stick together at a common final velocity v'. Thus
Both total momentums are equal:
Solving for v'
The data obtained from the question is
The first car travels north which means its velocity has only y-component
The second car travels east, only x-component of the velocity is present
Plugging in the values
The magnitude of the velocity is
And the angle
Answer:
ωB = 300 rad/s
ωC = 600 rad/s
Explanation:
The linear velocity of the belt is the same at pulley A as it is at pulley D.
vA = vD
ωA rA = ωD rD
ωD = (rA / rD) ωA
Pulley B has the same angular velocity as pulley D.
ωB = ωD
The linear velocity of the belt is the same at pulley B as it is at pulley C.
vB = vC
ωB rB = ωC rC
ωC = (rB / rC) ωB
Given:
ω₀A = 40 rad/s
αA = 20 rad/s²
t = 3 s
Find: ωA
ω = αt + ω₀
ωA = (20 rad/s²) (3 s) + 40 rad/s
ωA = 100 rad/s
ωD = (rA / rD) ωA = (75 mm / 25 mm) (100 rad/s) = 300 rad/s
ωB = ωD = 300 rad/s
ωC = (rB / rC) ωB = (100 mm / 50 mm) (300 rad/s) = 600 rad/s