25 kg
Explanation:
we can calculate the mass of the crate by using the Newton's second law:

where
F is the force acting on the crate
m is the mass
a is the acceleration
In this problem,
and
, so we can re-arrange the equation above to calculate the mass of the crate:

Differences b/w an motor n an electromagnet r :
1- motor is a device which converts electrical energy into mechanical energy while an electromagnet is just a combination of a soft iron core + solenoid....
2- electromagnets r strong temporary magnets while motors don't behave like a magnet
Answer:
30.63 m
Explanation:
Using y = ut + 1/2gt² where u = initial speed of block = 0 m/s, g = acceleration due to gravity = 9.8 m/s² and t = time of fall = 2.5 s and y = height of fall.
So, substituting the values of the variables into the equation, we have
y = ut + 1/2gt²
y = 0 m/s × 2.5 s + 1/2 × 9.8 m/s² × (2.5 s)²
y = 0 m + 4.9 m/s² × 6.25 s²
y = 0 m + 30.625 m
y = 30.625 m
y ≅ 30.63 m
So, the brick fell 30.63 m
Answer:
Bowling Ball: weight on Earth = 49 N
Textbook: Mass = 2 kg; weight on the moon = 3.2 N
Large dog: weight on Earth = 490 N; weight on the moon = 80 N
Law of Universal Gravitation: 
= gravitational force (Newtons/N)
<em>G</em> = gravitational constant, 6.67430 × 10¹¹ 
<em>m</em>₁ and <em>m</em>₂ = masses of two objects (kilograms/kg)
<em>r</em>² = square of distance between centers of the two objects (meters/m)
Have a fantastic day!