Answer:
a) Time = 2.67 s
b) Height = 35.0 m
Explanation:
a) The time of flight can be found using the following equation:
(1)
Where:
: is the final position in the horizontal direction = 80 m
: is the initial position in the horizontal direction = 0
: is the initial velocity in the horizontal direction = 30 m/s
a: is the acceleration in the horizontal direction = 0 (the stone is only accelerated by gravity)
t: is the time =?
By entering the above values into equation (1) and solving for "t", we can find the time of flight of the stone:
b) The height of the hill is given by:
Where:
: is the final position in the vertical direction = 0
: is the initial position in the vertical direction =?
: is the initial velocity in the vertical direction =0 (the stone is thrown horizontally)
g: is the acceleration due to gravity = 9.81 m/s²
Hence, the height of the hill is:
I hope it helps you!
Answer:
13.91 m/s
Explanation:
First we need to find the acceleration:
Acceleration = Force/mass
Acceleration = 36.7N/7.41 kg
Acceleration = 4.95 m/s² (rounded to two decimal places)
Then we find the velocity:
Velocity = Acceleration * Time
Velocity = 4.95 m/s² * 2.81 s
Velocity = 13.91 m/s (rounded to two decimal places)
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
The initial kinetic energy of the boat and its rider is
After Sam stops it, the final kinetic energy of the boat+rider is
because its final velocity is zero.
For the law of conservation of energy, the work done by Sam is the variation of kinetic energy of the system:
where the negative sign is due to the fact that the force Sam is applying goes against the direction of motion of the boat.
