Answer: 2940 J
Explanation: solution attached:
PE= mgh
Substitute the values:
PE= 10kg x 9.8 m/s² x 30 m
= 2940 J
<u>We are given:</u>
Mass of the rocket = 10 kg
Weight of the Rocket = 100 N
Upward thrust applied by the rocket = 400 N
<u>Net upward force on the rocket:</u>
We are given that gravity pulls the rocket with a force of 100 N
Also, the rocket applied a force of 400N against gravity
Net upward force = Upward thrust - Force applied by gravity
Net upward force = 400 - 100
Net upward force = 300 N
<u>Upward Acceleration of the Rocket:</u>
From newton's second law:
F = ma
<em>replacing the variables</em>
300 = 10 * a
a = 30 m/s²
<u>Answer:</u> The ball is travelling with a speed of 5.5 m/s after hitting the <u>bottle.</u>
<u>Explanation:</u>
To calculate the speed of ball after the collision, we use the equation of law of conservation of momentum, which is given by:

where,
are the mass, initial velocity and final velocity of ball.
are the mass, initial velocity and final velocity of bottle.
We are given:

Putting values in above equation, we get:

Hence, the ball is travelling with a speed of 5.5 m/s after hitting the bottle.
Answer:

Explanation:
Given:
The area of the house 
The height of the house 
We need to find the volume of a typical house.
Solution:
We find the volume of the house by multiplying the area of the house and height of the house.


Area and height of the house are known, so we substitute these value in above equation.


Now we convert the unit from feet to meter.
Divide the volume by 3.2808 for 


Therefore, the volume of the house is 
Answer: #4
Sally is faster.
Explanation:
If you multiply Sallies it is going to be less than Jessica's.