Displacement is the distance between the start- and end-points,
no matter what route is followed from start to finish.
If she travels around half of the circle, then her start- and end-points
are the two ends of a diameter, and her displacement is its length.
The length of the diameter is (2 x radius) = 6.84 meters.
Answer:
Explanation:
By conservation of energy, speed of the ball going up = speed of ball coming down with the ball stops at the top.
Because the gravity acceleration is constant, by symmetry, half of total time, 6/2 = 3s, is for going up and the last 3s for coming down.
Consider the last 3s when the ball drops from top to bottom, the initial velocity = 0 and acceleration = 10m/s^2
distance traveled = initial velocity * time + 1/2 * acceleration * time^2
= 0*3 + 1/2*10*3^2
= 5*9
= 45m
So maximum height of the ball is 45m.
Answer:
640 N
Explanation:
Given :
Mass of horse, m = 40kg
initial speed of horse, u = 8 m/s
final speed of horse, v = 0 m/s (because horse comes to a sudden stop)
time taken to stop, t = 0.5 s
recall that acceleration = change in speed / time taken for the change
or
a = (v - u) / t (substituting the above values)
a = (0 - 8) / 0.5
a = -16 m/s² (i.e it is a deceleration of 16 m/s²)
since we are not concerned about the direction of the force, we can simply use the absolute value of acceleration which is a = 16 m/s²
also recall that
Force = mass x acceleration
F = ma (substituting the values above)
F = 40kg x 16 m/s
F = 640 N
Answer:
The balloon will move forward.
The density of the air will be greater at the back of the balloon; similar
to the density of air being greater at lower altitudes due to gravitational
attraction because of the weight of the air in an air column.
A block of wood in water rises because of the difference in pressures
on the top and bottom of the block.
