First, we must find the vertical distance traveled upwards by the ball due to the throw. For this, we will use the formula:
2as = v² - u²
Because the final velocity v is 0 in such cases
s = -u²/2a; because both u and a are downwards, the negative sign cancels
s = 14.5² / 2*9.81
s = 10.72 meters
Next, to find the time taken to reach the ground, we need the height above the ground. This is:
45 + 10.72 = 55.72 m
We will use the formula
s = ut + 0.5at²
to find the time taken with the initial velocity u = 0.
55.72 = 0.5 * 9.81 * t²
t = 3.37 seconds
Answer:
Explanation:
Givens
m = 942
F = 6731
t = 21 seconds
vi = 0
vf = ?
Formula
F = m * (vf - vi ) / t
Solution
6731 = 942*(vf - 0)/21 Multiply both sides by 21
6731 * 21 = 942*vf
141351 = 942*vf Divide by 942
141351/942 = vf
vf = 151 m/s
Answer:
-2200 N
Explanation:
The change in momentum of Sarah is equal to the impulse, which is the product between the force exerted by the seatbelt on Sarah and the time during which the force is applied:
where
m is the mass
is the change in velocity
F is the average force
is the duration of the collision
In this problem:, we have:
m = 55 kg is Sarah's mass
is the change in velocity
is the duration of the collision
Solving for F, we find the force exerted by the seatbelt on Sarah:
Where the negative sign indicates that the direction of the force is opposite to that of Sarah's initial velocity.
The medium determines the speed of the wave traveling in it, which also can have a number of other effects, including how much the wave bends (refracts), whether it reflects, etc.
Because waves move through space, they must have a velocity. The velocity of a wave is a function of the type of wave, and the medium it travels through. Electromagnetic waves moving through a vacuum, for instance, travel at roughly 3 x
10
8
m/s. This value is so famous and common in physics it is given its own symbol, c.
Answer:
Originally : Level = log I / I0
Currently: Level = 10 log I / I0
Level = 10 log 600 = 10 * 2.78 = 27.8
Note the term 1 bel = 10 decibels
