Answer:
118 N
Explanation:
Given mass of the block, m = 4.00kg.
The acceleration of the elevator, a = 3.0 m/s^2.
As elevotar attaced with spring scale and accelerating upward
(block and elevator), so total force

Here, mg is the weight of the block downward direction.
or

substitute the given value, we get

= 117.6 N = 118 N.
Thus, the reading on the spring scale to 3 significant figures is 118 N.
Answer:
30000 J = 30 kJ
Explanation:
Kinetic energy is the energy possessed by a moving object solely due to its motion.
You can get the K.E. of an object using the equation,
K.E. = 
So you get,
K.E. = 
= 30000 J = 30 kJ
Explanation:
Speed is distance over time.
500 km / 2 hr = 250 km/hr
Velocity is speed and direction.
250 km/hr north
Answer:
The incident light ray which lands upon the surface is said to be reflected off the surface. The ray that bounces back is called the reflected ray. If a perpendicular were to be drawn on reflecting surface, it would be called normal. The figure below shows the reflection of an incident beam on a plane mirror.
Explanation:
10^9 giga, 10^6 mega, 10^3 kilo, 10^-3 milli, 10^-6 micro, 10^-9 nano, 10^-12 pico
Potentially they might want centi which is 10^-2