Answer:
The hammer and the wall exert forces on each other that are equal in magnitude but in opposite directions.
Explanation:
currently doing corrections on the test!
:)
According to given condition there is no height(m) given from roof of building to the ground, there height given 18 m at a point above the ground. So, h=18m , mass=3kg , g=9.8m/s2 P.E=mgh P.E=(3)(9.8)(18) P.E=529J
Answer: 0.5 seconds or 2.625 seconds
Explanation:
At t = 0, The ball is 4 ft above the ground.
The height of the football varies with time in the following way:
s(t) = -16 t² + 50 t + 4
we need to find the time in which the height would of the football would be 25 ft:
⇒25 = -16 t² + 50 t + 4
we need to solve the quadratic equation:
⇒ 16 t² - 50 t + 21 = 0
⇒ t = 0.5 s or 2.625 s
Therefore, at t = 0.5 s or 2.625 s, the football would be 25 ft above the ground.
<h3>
Answer:</h3>
172.92 °C
<h3>
Explanation:</h3>
Concept being tested: Quantity of heat
We are given;
- Specific heat capacity of copper as 0.09 cal/g°C
- Quantity of heat is 8373 calories
- Mass of copper sample as 538.0 g
We are required to calculate the change in temperature.
- In this case we need to know that the amount of heat absorbed or gained by a substance is given by the product of mass, specific heat capacity and change in temperature.
Therefore, to calculate the change in temperature, ΔT we rearrange the formula;
ΔT = Q ÷ mc
Thus;
ΔT = 8373 cal ÷ (538 g × 0.09 cal/g°C)
= 172.92 °C
Therefore, the change in temperature will be 172.92 °C
Answer:
4
Explanation:
For gases :
1. The motion of gases molecule is in random manner at the room temperature.
2.The distance between the gas molecule is more and that is why gas can be compress.
3.The attraction force between the gas molecule is negligible or we can say that there is no any force between the gas molecules.that is why gas can be filled in the container.But the motion of the gas molecule does not stop they are still moving inside the container but the space for movement become less.When a gas container heated then the container start to vibrate because the movement of the gas molecule.
So the option 4 is incorrect.
