Answer:
A) hydrostatic force on top of cube = 882.9N
B) hydrostatic force on sides of cube = 0N
Explanation:
Detailed explanation and calculation is shown in the image below
Answer: 2000 watts
Explanation:
Given that,
power = ?
Weight of object = 200-N
height = 4 m
Time = 4 s
Power is the rate of work done per unit time i.e Power is simply obtained by dividing work by time. Its unit is watts.
i.e Power = work / time
(since work = force x distance, and weight is the force acting on the object due to gravity)
Then, Power = (weight x distance) / time
Power = (200N x 4m) / 4s
Power = 8000Nm / 4s
Power = 2000 watts
Thus, 2000 watts of power is needed to lift the object.
To add vectors we can use the head to tail method (Figure 1).
Place the tail of one vector at the tip of the other vector.
Draw an arrow from the tail of the first vector to the tip of the second vector. This new vector is the sum of the first two vectors.

Explanation:
At the top of the tree, the velocity of the pebble is purely horizontal so we can calculate it as


Answer:
<h3> 1.40625m/s²</h3>
Explanation:
Using the equation of motion expressed as v = u+gt where;
v is the final velocity of the ball
u is the initial velocity
g is the acceleration due to gravity
t is the time taken
Given
u = 9m/s
v = 0m/s
t = 6.4s
Required
acceleration due to gravity g
Since the rock is thrown up, g will be a negative value.
v = u+(-g)t
0 = 9-6.4g
-9 = -6.4g
6.4g = 9
divide both sides by 6.4
6.4g/6.4 = 9/6.4
g = 1.40625m/s²
Hence the acceleration due to gravity on the planet is 1.40625m/s²