Answer:
1) Potential energy (gravitation)
2)Potential energy
3)Kinetic energy
4) Kinetic energy
5)Potential energy
6)Kinectic energy
7)Potential energy (elastic)
Hope it helps
Answer:
Q (heat) = S * m * (T2 - T1) where Q is heat gained (loss), S the specific heat capacity of the substance and T2, T1 are the final and initial temps
Q = .215 cal / (g deg C) * 5 g * (20 - 80) deg C = -64.5 cal
Since the question specifies the heat emitted, then 64.5 cal is the
heat emitted (loss).
Answer:
(a)

(b)
1120 N
Explanation:
Change in velocity,
is given by subtracting the initial velocity from the final velocity and expressed as 
Where v represent the velocity and subscripts f and i represent final and initial respectively. Since the ball finally comes to rest, its final velocity is zero. Substituting 0 for final velocity and the given figure of 8 m/s for initial velocity then the change in velocity is given by

To find
then we substitute 7 kg for m and -8 m/s for
therefore 
(b)
The impact force, F is given as the product of mass and acceleration. Here, acceleration is given by dividing the change in velocity by time ie

Substituting t with 0.05 s then 
Since F=ma then substituting m with 7 Kg we get that F=7*-160=-1120 N
Therefore, the impact force is equivalent to 1120 N
Magnetic field describea magnet's ability to act at a distance
Answer:
Tension = 0.012 N
Explanation:
If the black widow spider is hanging vertically motionless from the ceiling above. Then, the weight of the spider must be balancing the tension in the spider web. Therefore,
Tension = Weight
Tension = mg
where,
m = mass of spider = 1.27 g = 0.00127 kg
g = acceleration due to gravity = 9.8 m/s²
Therefore,
Tension = (0.00127 kg)(9.8 m/s²)
<u>Tension = 0.012 N</u>