Answer:
Answer D : about 1067 meters
Explanation:
There are two steps to this problem:
1) First find the time it takes the plane to stop using the equation for the acceleration:

Where Vf is the final velocity of the plane (in our case: zero )
Vi is the initial velocity of the plane (in our case: 80 m/s)
is the acceleration (in our case -3 m/s^2 - notice negative value because the velocity is decreasing)

with units corresponding to seconds given the quantities involved in the calculation.
2) Second knowing the time it took the plane to stop, now use that time in the equation for the distance traveled under accelerated motion:

Where the answer results in units of meters given the quantities used in the calculation.
We round this to 1067 meters
Answer:
207.4 N
Explanation:
The torque
on a body is
where r is the radius vector from the point of rotation to the point at which force F is applied.
The product of r and F is equal to the product of magnitude of r and F multiplied by the sine of angle between both vectors.
Therefore, torque is also given by
Where
is the angle between r and F.
Use the expression of torque.
Substitute L for r in the equation
Where L is the length of the wrench.
Making F the subject
Force required to pull the wrench is given as,
Substitute
for
, 25 cm for L, and 115o for
Answer:
Hz
Explanation:
We know that
1 cm = 0.01 m
= Length of the human ear canal = 2.5 cm = 0.025 m
= Speed of sound = 340 ms⁻¹
= First resonant frequency
The human ear canal behaves as a closed pipe and for a closed pipe, nth resonant frequency is given as

for first resonant frequency, we have n = 1
Inserting the values


Hz
Speed=30 m/s - 1.5 m/s = 28.5 m/s forward