The correct answer is C.) a leaf
Answer:
52.5 m
Explanation:
The displacement is the area under the velocity vs time graph.
From 0 to 5 seconds, the area is the area of the triangle plus the area of the rectangle.
x = ½ (3 s) (15 m/s) + (2 s) (15 m/s)
x = 52.5 m
A 60.0 kg secretary running up a 4.0 m tall flight of stairs in 4.2 s has an average power of 560 W (Option b).
<h3>What is power?</h3>
Power is the work done over a period of time.
A secretary with a mass (m) of 60.0 kg runs up a 4.0 m (d) tall flight of stairs. Given gravity (g) is 9.81 m/s², the work (W) done is:
W = m × g × d = 60.0 kg × 9.81 m/s² × 4.0 m = 2.35 × 10³ J
They do 2.4 × 10³ J of work in 4.2 s (t). The average power (P) is:
P = W / t = 2.35 × 10³ J / 4.2 s = 560 W
A 60.0 kg secretary running up a 4.0 m tall flight of stairs in 4.2 s has an average power of 560 W (Option b).
Learn more about power here: brainly.com/question/911620
#SPJ1
Answer:
When the bat hits the ball, it exerts some force on the ball. Just think about a home run hitter hitting a stationary ball. How far do you think it will go? Will it go more than 400 ft.? Probably not. While the kinetic energy transferred from the bat to the ball accounts for some energy of the ball, it does not account for all. Where is the mysterious energy coming from?
The answer is conservation of momentum. I just said momentum is conserved but how do I know that? I know that because of Newton's 2nd law: F=ma (Force equals mass times acceleration)
Conservation of momentum means that the harder you throw you, the harder the ball will bounce back at you. That is the reason it is easier to hit a home run on a fast ball than a curveball.
Conservation of momentum also means that the bat can transfer some of its momentum to the ball. This is why it is better to use a heavier bat if you swing just as fast. The momentum is the product of the mass and velocity, so to make it easier to understand;
a heavier bat swung at the same speed as a lighter bat will have more momentum.
