Complete question is;
A rocket ship starts from rest and turns on its forward booster rockets, causing it to have a constant acceleration of 4 m/s² rightward. After 3s, what will be the velocity of the rocket ship?
Answer:
v = 12 m/s
Explanation:
We are given;
Initial velocity; u = 0 m/s (because ship starts from rest)
Acceleration; a = 4 m/s²
Time; t = 3 s
To find velocity after 3 s, we will use Newton's first equation of motion;
v = u + at
v = 0 + (4 × 3)
v = 12 m/s
Answer: 0.25 m/s
Explanation: Speed = wavelengt · frequency
v = λf and frequency is 1/period f = 1/T
Then v = λ/T = 5 m / 20 s = 0.25 m/s
- Mass of the elevator (m) = 570 Kg
- Acceleration = 1.5 m/s^2
- Distance (s) = 13 m
- Let the force be F.
- We know, F = ma,
- Therefore, F = (570 × 1.5) N = 855 N
- Angle between distance and force (θ) = 0°
- We know, work done = F s Cos θ
- Therefore, work done by the cable during this part
- = (855 × 13 × Cos 0°) J
- = (855 × 13 × 1) J
- = 11115 J
<u>Answer</u><u>:</u>
<u>1</u><u>1</u><u>1</u><u>1</u><u>5</u><u> </u><u>J</u>
Hope you could get an idea from here.
Doubt clarification - use comment section.
The answer is D. The Ossicles
The mass of ball a is twice the mass of ball b:

This means that the initial potential energy of ball a (

) is twice the potential energy of ball b (

):

When the two balls reach the ground, the potential energy of each ball has converted into kinetic energy (since now their altitude is h=0), because the total mechanical energy of each ball must be conserved. Therefore:


and so the kinetic energy of ball a must be twice the kinetic energy of ball b: