Answer:
a. Gravity and c. Spring
Explanation:
Formula for work energy 
whereas F is the force acting on the block, S is the distance traveled, and
is the angle between 2 vectors F and S.
If F is perpendicular to S, then



a. Normal force is the reaction force acting from the ramp back on the wooden block. This force is perpendicular to the direction of sliding. Therefore this force would do no work.
b. Gravity is the force acting downward, this would have an angle of
degrees so the work is non-zero.
c. Spring force would have the same direction as sliding so the work is non-zero.
d. Friction force would have the same direction as sliding. However, as this is a frictionless ramp, the friction coefficient would be 0. Friction force would also be zero and so as its work.
I sincerely do not know the formula but using normal maths i got 1.71cm
Answer:
Astronauts float around in space because there is no gravity in space. Everyone knows that the farther you get from Earth, the less the gravitational force is. Well, astronauts are so far from the Earth that gravity is so small. This is why NASA calls it microgravity.
Explanation:
Answer:
3.67 N
Explanation:
From the question given above, the following data were obtained:
Charge of 1st object (q₁) = +15.5 μC
Charge of 2nd object (q₂) = –7.25 μC
Distance apart (r) = 0.525 m
Force (F) =?
Next, we shall convert micro coulomb (μC) to coulomb (C). This can be obtained as follow:
For the 1st object
1 μC = 1×10¯⁶ C
Therefore,
15.5 μC = 15.5 × 1×10¯⁶
15.5 μC = 15.5×10¯⁶ C
For the 2nd object:
1 μC = 1×10¯⁶ C
Therefore,
–7.25 μC = –7.25 × 1×10¯⁶
–7.25 μC = –7.25×10¯⁶ C
Finally, we shall determine the force. This can be obtained as follow:
Charge of 1st object (q₁) = +15.5×10¯⁶ C
Charge of 2nd object (q₂) = –7.25×10¯⁶ C
Distance apart (r) = 0.525 m
Electrical constant (K) = 9×10⁹ Nm²/C²
Force (F) =?
F = Kq₁q₂ / r²
F = 9×10⁹ × 15.5×10¯⁶ × 7.25×10¯⁶ / 0.525²
F = 3.67 N
Therefore, the force on the object is 3.67 N