The equation of GPE is mgH, where m is mass, g is gravitational acceleration, and H is the height.
If we're solving for the change in GPE, then:
∆
= mg∆H
<u>Input our given values for m and g:</u>
∆
= 0.25 * 9.80 * ∆H
<u>The book falls from 2 meters high to 0.5 meters high, so:</u>
∆
= 0.25 * 9.80 * (2.0 - 0.5)
∆
= 0.25 * 9.80 * 1.5
∆
= 3.675 (J)
<u>Adjust for significant figures:</u>
∆
= 3.7 (J)
The change in gravitational potential energy was 3.7 (J)
If you have any questions on anything I did to get to the answer, just ask!
- breezyツ
Answer:
The initial speed of the ball is 30 m/s.
Explanation:
It can be assumed that the ball is thrown at an angle of 45 degrees to the ground. The ball lands 90 m away. We need to find the initial speed of the ball. We know that the horizontal distance covered by the projectile is called its range. It is given by :

u is the initial speed of the ball.


v = 29.69 m/s
or
v = 30 m/s
So, the initial speed of the ball is 30 m/s. Hence, this is the required solution.
Answer:
If you know that that free fall acceleration g on the Moon is about 6 times less than on the Earth, it gives you the answer: on the Moon the same pendulum will have a period about √6≈2.45 longer than on the Earth.