2. A 200.0-kg bear grasping a vertical tree slides down at constant velocity. What is the friction force between the tree and th
1 answer:
Answer: 1960 N
Explanation:
The bear is sliding down at constant velocity: this means that its acceleration is zero, so the net force is also zero, according to Newton's second law:
There are two forces acting on the bear: its weight W, pulling downward, and the frictional force Ff, pulling upward. Therefore, the net force is given by the difference between the two forces:
From the previous equation, we find that the frictional force is equal to the weight of the bear:
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Answer:
5.68 m/s
Explanation:
The motion of the salmon is the same as a projectile: it is launched with an initial speed at an angle of
above the horizontal.
The motion of the salmon consists of two indipendent motion:
- Along the horizontal direction, it is a uniform motion with constant velocity
So that the distance travelled is
(1)
- Along the vertical direction, it is a uniformly accelerated motion with constant acceleration downward, so the vertical displacement is
(2)
where g is the acceleration of gravity.
We know the following:
- The horizontal distance travelled by the salmon to reach the waterfall is
d = 2.33 m
- The vertical distance travelled is the height of the waterfall,
y = 0.488 m
From (1) we get:
And substituting into (2), we can solve the equation to find t, the time at which the salmon reaches the waterfall:
And then, we can use eq.(1) again to find the initial speed, u:
Answer:
It will take 29.31 seconds for the Boxster to catch the Scion
Explanation:
Given the data in the question;
lets say Toyota Scion xB is car A and Porsche Boxster convertible is B and Toyota Scion xB is car A
the distance travelled by car A is
x = × t
where is the speed of the car and t is time
the distance travelled by car B before reaching car A will be;
x + x₀ = × t
Now lets replace x by × t
so
( × t) + x₀ =
× t
x₀ = ( × t) - (
× t)
x₀ = t ( -
)
t = x₀ / ( -
)
so we substitute
t = 170 m / (24.4 - 18.6)
t = 170 / 5.8
t = 29.31 s
Therefore; it will take 29.31 s for the Boxster to catch the Scion