The answer is Alternating Current
Answer:
A. Speed
Explanation:
A vector quantity is a quantity which has both magnitude and direction. Here in the given options, speed is a scalar quantity but not the vector quantity.
Answer:
D. a person pulling a sled.
Explanation:
contact force only occurs when something directly comes in contact with another object.
a. is wrong because that is called magnetic force.
b. gravitational force
c. is an electrical force
formula for gravitational P.E =mgh
Solution:-mass=3kg height=5metre and gravity=9.8 or 10m/sec² so P.E=mgh , 3×9.8×5=147kgm²/sec²
Answer:
Groceries stay in the bag.
Explanation:
Given:
Maximum force = 250 N
Bag filled with = 20 kg
Lifted acceleration = 
Solution:
We need to calculate the exerted force on the grocery bag by using Newton's second law.

Where:
F = Exerted force on the object.
m = Mass of the object in kg
a = Acceleration of the object in 
Now, we substitute m = 20 kg and a =
in Newton's second law,


Since, the exerted force on the bag is less than 250 N, the groceries will stay in the bag.