Let F be the magnitude of the frictional force. This force performs an amount of work W on the bullet such that
W = -Fx
where x is the distance over which F is acting. This is the only force acting on the bullet as it penetrates the tree. The work-energy theorem says the total work performed on a body is equal to the change in that body's kinetic energy, so we have
W = ∆K
-Fx = 0 - 1/2 mv²
where m is the body's mass and v is its speed.
Solve for F and plug in the given information:
F = mv²/(2x)
F = (0.00426 kg) (881 m/s)² / (2 (0.0444 m))
F = 37,234.8 N ≈ 37.2 kN
Answer:
Between 120 and 180 seconds
A. planets do not affect birth defects
Answer:
d) Decrease, increase, remain constant
Explanation:
If one tire has a slow leak, the air pressure within the tire will_DECREASE____with time due to outflow of air , the surface area between the tire and the road will__INCREASE__in time,due to flattening of tire.
The net force the tire exerts on the road will_REMAIN CONSTANT____in time. It is so because force does not depend upon area. It is pressure which depends upon area. As there is no change in the weight of the car , force on the road will remain constant.
Answer:
Explanation:
We should first find the velocity and acceleration functions. The velocity function is the derivative of the position function with respect to time, and the acceleration function is the derivative of the velocity function with respect to time.
Similarly,
Now, the angle between velocity and acceleration vectors can be found.
The angle between any two vectors can be found by scalar product of them:
So,
At time t = 0, this equation becomes
