Answer:
Shawn's kinetic energy is 61.45 J.
Explanation:
Given;
Mass of the system is,
Displacement of the bike is,
Time taken is,
Let the constant velocity be .
For constant velocity, magnitude of velocity is given as distance by time.
Therefore,
Now, kinetic energy of a body is given as:
Here,
Therefore, Shawn's kinetic energy is 61.45 J.
Answer:
B.The force of friction between the block and surface will decrease.
Explanation:
The force of friction is given by
where is the coefficient of friction and is the normal force.
When the student pulls on the block with force at an angle , the normal force on the block becomes
and hence the frictional force becomes
.
Now, as we increase , increases which as a result decreases the normal force , which also means the frictional force decreases; Hence choice B stands true.
<em>P.S: Choice D is tempting but incorrect since the weight </em><em> is independent of the external forces on the block. </em>
Answer: m∠P ≈ 46,42°
because using the law of sines in ΔPQR
=> sin 75°/ 4 = sin P/3
so ur friend is wrong due to confusion between edges
+) we have: sin 75°/4 = sin P/3
=> sin P = sin 75°/4 . 3 = (3√6 + 3√2)/16
=> m∠P ≈ 46,42°
Explanation: