Answer:
Positive
Explanation:
In an endothermic reaction, the products are at a higher energy than the reactants. This means that the enthalpy change of the reaction (∆H) is positive
Answer:
2.2N
Explanation:
Given parameters:
Work done = 379.5J
Height = 173m
Unknown:
Amount of force exerted on the sled = ?
Solution:
The amount of force she exerted on the sled is the same as her weight.
Work done is the force applied to move a body through a distance.
Work done = mgh
m is the mass
g is the acceleration due to gravity
h is the height
mg = weight;
Work done = weight x h
379.5 = weight x 173
weight =
= 2.2N
Answer: The bond that hold water molecules together are due to shared electrons. The bond of shared electrons is known as a covalent bond.
Explanation: Water is held together by bonds known as covalent bonds, in which electrons are shared by the elements. In this case, the two hydrogen atoms and the one oxygen atom share a bond in which they share electrons, attaining a full outer shell.
Given that,
Mass of a tribble, m = 2.5 kg
Radius, r = 1.4 m
The force on the tribble from the bucket does not exceed 10 times its weight.
To find,
The maximum tangential speed.
Solution,
The force acting on the tribble is equal to the centripetal force.
F = 10mg
The formula for the centripetal force is given by :

v is maximum tangential speed

So, the maximum tangential speed is 11.7 m/s.