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:
C) amplitude
Explanation:
"The amplitude is a measure of the strength or intensity of the wave. For example, when looking at a sound wave, the amplitude will measure the loudness of the sound. The energy of the wave also varies in direct proportion to the amplitude of the wave."-Ducksters
Answer: Technician B
Explanation: In manual cars,the clutch safety is designed to stop the vehicle from moving when you start the gnition. It prevents power from flowing into the circuit . This is found in the pedal mechanism of cars so depressing the clutch pedal will likely cause a defective in the clutch safety. You will begin to perceive the clutch burning and white fumes coming out from the pedal.
