Answer:
ma = 48.48kg
Explanation:
To find the mass of the astronaut, you first calculate the mass of the chair by using the information about the period of oscillation of the empty chair and the spring constant. You use the following formula:
(1)
mc: mass of the chair
k: spring constant = 600N/m
T: period of oscillation of the chair = 0.9s
You solve the equation (1) for mc, and then you replace the values of the other parameters:
(2)
Next, you calculate the mass of the chair and astronaut by using the information about the period of the chair when the astronaut is sitting on the chair:
T': period of chair when the astronaut is sitting = 2.0s
M: mass of the astronaut plus mass of the chair = ?
(3)
Finally, the mass of the astronaut is the difference between M and mc (results from (2) and (3)) :

The mass of the astronaut is 48.48 kg
<h3><u>Answer</u>;</h3>
C. An object can have acceleration with negative velocity.
<h3><u>Explanation</u>;</h3>
- Acceleration is a measure of the change in velocity over time. The change in velocity is measured in meter per second (m/s), and time interval is measured in second (s).
- Therefore, acceleration measures the change in meters per second every second [(m/s)/s], namely meters per second per second or meters per second squared (m/s2).
- If an object has zero acceleration, its velocity doesn’t have to be zero. Acceleration is a measure of the change in velocity over time. Zero acceleration means there is no change in velocity over time, namely constant velocity.
It's D. By "net" they mean the overall force the object experiences, so sum all the force vectors, those in a negative direction (eg friction) should be subtracted.
Answer:
Height of tower = 480 meter
Explanation:
Given:
Initial velocity = 20 m/s
Time taken to reach ground = 8 second
So,
Final velocity = 0 m/s
Acceleration due to gravity = 10 m/s²
Find:
Height of tower
Computation:
s = ut + (1/2)(g)(t)²
s = (20)(8) + (1/2)(10)(8)²
s = 160 + (1/2)(10)(64)
s = 160 + (10)(32)
s = 160 + 320
s = 480 meter
Height of tower = 480 meter