Answer:
49 km/h
Explanation:
60 km/h acceleration for 0.75 hours.
60 × 3/4 = 45 km/h
Take the acceleration and add it to the speed the train was already moving at:
45 + 4 = 49km/h
B.the speed of the car always increases, giving it greater force since the mass will remain the same.
C.the car now has a greater overall mass - its own mass plus the mass of the object by which it has been struck.
D.the people in the car will continue to move in the same direction and at the same speed as before the impact.
When an impact causes the car to suddenly change its motion, (D) the people in the car will continue to move in the same direction and at the same speed as before the impact.
Newton's first law of motion states that Unless influenced by an imbalanced force, a body at rest stays at rest, and a body in motion keeps moving in a straight path at a constant pace. This law is commonly known as law of inertia and the resistance of a body to maintain its state of rest is called inertia of rest, same as, the resistance of a body to maintain its state of motion is called inertia of motion.
When a car is moving with certain speed, the car along with the people inside the car is in inertia of motion. In an event of accident, the car comes in rest in no time but the man in the car is still in inertia of motion. So, his body moves forward in the car which may cause injuries. To prevent such injuries, the people inside a car are advised to use safety belts.
So, correct answer is option (D).
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Answer:
D :)
Explanation:
The velocity of a 500-kilogram elevator that has 4,000 joules of energy is 4m/s.
KINETIC ENERGY:
K.E = ½m.v²
Where;
m = mass of the elevator (kg)
v = velocity of the elevator (m/s)
V = √K.E × 2/m
V = √4000 × 2/500
V = √8000/500
V = √16
V = 4m/s
Learn more: brainly.com/question/10703928?referrer=searchResults
Rock concerts and whispers are examples of a high-amplitude sound and a low-amplitude sound.
The largest displacement of sound wave constituents from their resting positions is referred to as amplitude. It stands for the loudness or intensity of a sound, to put it simply. Here are some illustrations of both high and low-amplitude sounds:
High Amplitude Sound: An illustration of a high amplitude sound is a rock concert with loudspeakers blaring songs at full intensity. The concert speakers produce sound waves with a tremendous amplitude, creating a powerful, strong sound that can be heard from a great distance.
Low Amplitude Sound: A low amplitude sound is something like the sound of a whisper. The sound created when someone whispers is calm and soft and not as loud as a rock concert, since the sound waves produced have a tiny amplitude.
In both cases, how loud or soft the sound is perceived by our ears depends on the amplitude of the sound waves. Low-amplitude sounds are soft and quiet, but high-amplitude sounds are strong and loud.
Hence, rock concerts and whispers are examples of a high-amplitude sound and a low-amplitude sound.
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