Answer:
C. Waves transfer energy, but not matter.
Explanation: hope this helps :)
Answer:
Net pull = 110 N to the left
Explanation:
Group the different pulls according to the direction (right or left)
2 pull 196 N each to the right
4 pull 98 N each to the left
5 pull 62 N each to the left
3 pull 150 N each to the right
1 pull 250 N to the left
Since positive direction is to the right, the pulls to the left will have a minus (-)
The resulting force is negative, meaning the direction is to the left
The correct statements are that the speed decreases as the distance decreases and speed increases as the distance increases for the same time.
Answer:
Option A and Option B.
Explanation:
Speed is defined as the ratio of distance covered to the time taken to cover that distance. So Speed = Distance/Time. In other words, we can also state that speed is directly proportional to the distance for a constant time. Thus, the speed will be decreasing as there is decrease in distance for the same time. As well as there will be increase in speed as the distance increases for the same time. So option A and option B are the true options. So if there is decrease in the distance due to direct proportionality the speed will also be decreasing. Similarly, if the distance increases, the speed will also be increasing.
Answer:
K.E = 30,000 J
Explanation:
Given,
The potential energy of the roller coaster car, P.E = 40000 J
The kinetic energy at height h/4, K.E = ?
According to the law of conservation of energy, the total energy of the system is conserved.
At height 'h', the total energy is,
P.E = mgh
K.E = 0
At height 'h/4', the total energy is
P.E + K.E = mgh
P.E = mgh/4
K.E = 1/2 mv²
Therefore,
mgh/4 + 1/2 mv² = mgh
gh/4 + v²/2 = gh
Hence,
v² = 3gh/2
Substituting in the K.E equation
K.E = 1/2 mv²
= 1/2 m (3gh/2)
= 3/4 mgh
= 3/4 x 40000
= 30000 J
Hence, the K.E of the roller coaster car is, K.E = 30000 J
