Answer:
PE = 44.1 J
Explanation:
Ok, to have the specific data, the first thing we must do is convert from grams to kilograms. Since mass must always be in kilograms (kg)
We have:
- 1 kilograms = 1000 grams.
We convert it using a rule of 3, replacing, simplifying units and solving:
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Earth's gravity is known to be 9.8 m/s², so we have:
Data:
- m = 0.3 kg
- g = 9.8 m/s²
- h = 15 m
- PE = ?
Use formula of potencial energy:
Replace and solve:
Since the decimal number, that is, the number after the comma is less than 5, it cannot be rounded, then we have this result.
The potential energy of the volleyball is <u>44.1 Joules.</u>
Greetings.
Answer:
<em>The force required is 3,104 N</em>
Explanation:
<u>Force</u>
According to the second Newton's law, the net force exerted by an external agent on an object of mass m is:
F = ma
Where a is the acceleration of the object.
On the other hand, the equations of the Kinematics describe the motion of the object by the equation:

Where:
vf is the final speed
vo is the initial speed
a is the acceleration
t is the time
Solving for a:

We are given the initial speed as vo=20.4 m/s, the final speed as vf=0 (at rest), and the time taken to stop the car as t=7.4 s. The acceleration is:


The acceleration is negative because the car is braking (losing speed). Now compute the force exerted on the car of mass m=1,126 kg:

F= 3,104 N
The force required is 3,104 N
Answer:
System D --> System C --> System A --> System B
Explanation:
The gravitational force between two masses m1, m2 separated by a distance r is given by:

where G is the gravitational constant. Let's apply this formula to each case now to calculate the relative force for each system:
System A has masses m and m separated by a distance r:

system B has masses m and 2m separated by a distance 2r:

system C has masses 2m and 3m separated by a distance 2r:

system D has masses 4m and 5m separated by a distance 3r:

Now, by looking at the 4 different forces, we can rank them from the greatest to the smallest force, and we find:
System D --> System C --> System A --> System B
Answer:
(a) Power= 207.97 kW
(b) Range= 5768.6 meter
Explanation:
Given,
Mass of bullet, 
Kinetic energy imparted, 
Length of rifle barrel, 
(a)
Let the speed of bullet when it leaves the barrel is
.
Kinetic energy, 



Initial speed of bullet, 
The average speed in the barrel,

Time taken by bullet to cross the barrel, 

Power,

(b)
In projectile motion,
Maximum height, 
Range, 
given that, 
then, 
D) Less than 20.
Explanation:
Equivalent resistance in a parallel combination is less than their individual value.