Answer:
C
Explanation:
An object in motion will stay in motion unless acted on by a net positive or negative force.
For answer A. If the object were to be in an orbit, it would inevitably accelerate due to it being acted on by the gravitational force from the object it is orbiting. At different points in the orbit, the object will move at different speeds and continuously transfer between kinetic and potential energy.
For answer B. The object would would not stop their motion. In order for the object to lose energy, it would have to transfer it through friction or through its interaction with a gravitational field.
For answer D. No energy is "required" to maintain constant motion unless the object is willingly fighting against a resistive force like friction or a graviational well.
Answer:
(e) 98,1 KJ
Explanation:
The engine produces 19%; it means, it rejects 81% of energy. ⇒ 81/19=4.26 times.
The engine produces 23 kJ; it means it rejects 23 * 4.26 = 98.05263 kJ
Answer:
f = 3.1 kHz
Explanation:
given,
length of human canal =2.8 cm = 0.028 m
speed of sound = 343 m/s
fundamental frequency = ?
The fundamental frequency of a tube with one open end and one closed end is,



f = 3062.5 Hz
f = 3.1 kHz
hence, the fundamental frequency is equal to f = 3.1 kHz
Answer:
The girl has greater tangential acceleration
Explanation:
The angular acceleration (
) of the merry go round is equal to the rate of the change of the angular velocity,
:

Since all the points of the merry go round complete 1 circle in the same time, the angular velocity of each point of the merry go round is the same, and so all the points also have the same angular acceleration.
The tangential acceleration instead is given by

where
is the angular acceleration
r is the distance from the centre of the merry go round
Since the girl is near the outer edge and the boy is closer to the centre, the value of r for the girl is larger than for the boy, so the girl has greater tangential acceleration.