Answer:
426.84 m
Explanation:
initial velocity u = 0
time t = 3.3 s
distance travelled s = 53.4 m
acceleration due to gravity = g
s = ut + 1/2 g t²
53.4 = 0 + 1/2 g x 3.3²
g = 9.8 m /s²
For the whole length of fall
distance travelled = h
total time = 6.6 + 3.3 = 9.9 s
h = ut + 1/2 g t²
u again = 0
h = .5 x 9.8 x 9.9²
= 480.24 m
distance travelled in last 6.6 s
= 480.24 - 53.4
= 426.84 m
Answer:
The new force is 1/4 of the previous force.
Explanation:
Given
---- 
--- 
Required
Determine the new force
Let the two particles be q1 and q2.
The initial force F1 is:
--- Coulomb's law
Substitute 2 for r1


The new force (F2) is

Substitute 4 for r2



Substitute 


The new force is 1/4 of the previous force.
Answer:
30.63 m
Explanation:
From the question given above, the following data were obtained:
Total time (T) spent by the ball in air = 5 s
Maximum height (h) =.?
Next, we shall determine the time taken to reach the maximum height. This can be obtained as follow:
Total time (T) spent by the ball in air = 5 s
Time (t) taken to reach the maximum height =.?
T = 2t
5 = 2t
Divide both side by 2
t = 5/2
t = 2.5 s
Thus, the time (t) taken to reach the maximum height is 2.5 s
Finally, we shall determine the maximum height reached by the ball as follow:
Time (t) taken to reach the maximum height = 2.5 s
Acceleration due to gravity (g) = 9.8 m/s²
Maximum height (h) =.?
h = ½gt²
h = ½ × 9.8 × 2.5²
h = 4.9 × 6.25
h = 30.625 ≈ 30.63 m
Therefore, the maximum height reached by the cannon ball is 30.63 m
Answer:

Explanation:
For this case we can use the second law of Newton given by:

The friction force on this case is defined as :

Where N represent the normal force,
the kinetic friction coeffient and a the acceleration.
For this case we can assume that the only force is the friction force and we have:

Replacing the friction force we got:

We can cancel the mass and we have:

And now we can use the following kinematic formula in order to find the distance travelled:

Assuming the final velocity is 0 we can find the distance like this:

Answer:
Part a)

Part b)

Part c)

Explanation:
As we know that 5000 kg African elephant requires 70,000 Cal for basic needs per day
so we will have


so we have energy required per kg


Part a)
now we know that per kg the energy required will be same
so we have mass of the human is 68 kg
so energy required per day is given as


Part b)
Resting power is the rate of energy in Joule required per sec
so it is given as


Part c)
resting power given in the book is

so this is less than the power given

