The force of gravity is the only force that keeps a pendulum in motion. both the force increases the speed of the pendulum on the downswing and decreases it's speed on its upswing.
Answer:
3.75s
Explanation:
a = 8.0 m/s V = 30 m/s U = 0 m/s t = ?
t = V - U/a
t = 30 - 0/8
t = 30/8 = 15/4
t = 3.75s
The power P in watts (W) is equal to the energy E in joules (J), divided by the time period t in seconds (s):
P(W) = E(J) / t(s)
2.78 Watts
Answer:
a) 
, 
, b) 
, c) 
, d) 
, e) 
Explanation:
a) The velocity function is determined by deriving the position function in time:
Velocities after 2 seconds and 4 seconds are, respectively:
b) The maximum height is reached when velocity is equal to zero:
The time when the projectile reaches the maximum height:
c) The maximum height is:
d) The projectile hits the ground when height is equal to zero:
The roots of the second order polynomial are presented below:
The first one is the only reasonable solution in physical terms.
e) The velocity of the projectile when it hits the ground is:
Answer:
The answer is below
Explanation:
A cross-country skier moves 28 meters westward, then 62 meters eastward, and finally 54 meters westward.
For this motion, what is the distance moved?
What is the magnitude and direction of the displacement?
Answer:
a) The distance moved is the summation of all the distance, therefore:
Distance = Distance first moved westward + Distance moved eastward + Final distance moved westward = 28 m + 62 m + 54 m = 144 m
Distance = 144 m
b) Displacement is a vector quantity (has magnitude and direction). The displacement is the shortest distance from the starting to final point.
Total distance westward = 28 m + 54 m = 82 m
Total distance eastward = 62 m
Displacement = Total distance westward - Total distance eastward = 82 m - 62 m = 20 m
Displacement = 20 m westward
The displacement has a magnitude of 20 m and the direction is westward
