An object that is moving in a linear path with an acceleration in the direction opposite to the motion has a(n) _______changing_______ velocity.
Answer:
Time, t = 13.34 seconds.
Explanation:
Given the following data;
Initial velocity, u = 85km/hr to meters per seconds = 85*1000/3600 = 23.61 m/s
Final velocity, v = 45km/hr to meters per seconds = 45*1000/3600 = 12.5 m/s
Acceleration, a = -3 km/hr/sec to meters per seconds square = -3*1000/3600 = -0.833m/s²
To find the time;
Acceleration = (v - u)/t
-0.833 = (12.5 - 23.61)/t
-0.833t = -11.11
t = 11.11/0.833
Time, t = 13.34 seconds.
Answer:
KE + PE = KE + PE
Explanation:
In a closed system, the mechanical energy of the system is constant.
Mechanical energy is given by the sum of kinetic energy and potential energy; mathematically:
U = KE + PE
where
KE is the kinetic energy
PE is the potential energy
This means that if we consider two situations, one at the beginning and one at the end, the value of U will not change if the system is closed; this means that the sum KE + PE will remain the same, so we can write:
KE + PE = KE + PE
Answer:
The velocity must change but not speed.
Explanation:
- Velocity is defined as the displacement by time. Whereas speed is expressed as the distance between two successive positions of the body to the time interval it took to travel.
<em>Velocity, V = D / t m/s</em>
<em> Speed, s = d /t m/s </em>
- Velocity is a vector quantity that has a magnitude and direction.
- The speed is a scalar quantity having only the magnitude.
- At any instant of time, the magnitude of the velocity is always equal to the magnitude of the speed. The magnitude of velocity, |<em>v </em>| = magnitude of speed, |<em>v </em>|. The magnitude is always positive
- The acceleration of a body is defined as the rate of change of velocity to time.
<em> a = (v - u) / t m/s²</em>
- If a body is accelerating, It varies its velocity with respect to time.
- In case of uniform circular motion, the speed remains constant, but the velocity changes continuously.
So, in the case of circular motion if an object accelerates, velocity must change but speed remains constant.
Answer:
The answer is below
Explanation:
The amplitude decreases by 2% during each oscillation. Hence the decrease in amplitude can be represented by an exponential decay in the form:
y = abˣ; where x ad y are variables, a is the initial value and b is the factor.
Let y represent the amplitude after x oscillations. Since the initial amplitude is 10 cm, hence:
a = 10 cm, b = 2% = 0.02.
Therefore:
y = 10(0.02)ˣ
The amplitude after 25 oscillations is gotten by substituting x = 25 into the equation. Hence:
y = 10(0.02)²⁵
y= 3.355 * 10⁻⁴² cm
The amplitude after 25 oscillations is 3.355 * 10⁻⁴² cm
