Answer:
7500 m
Explanation:
The radar emits an electromagnetic wave that travels towards the object and then it is reflected back to the radar.
We can call L the distance between the radar and the object; this means that the electromagnetic wave travels twice this distance, so
d = 2L
In a time of
Electromagnetic waves travel in a vacuum at the speed of light, which is equal to
Since the electromagnetic wave travels with constant speed, we can use the equation for uniform motion ,so:
(1)
where
, where L is the distance between the radar and the object
Re-arranging eq(1) and substituting, we find L:
_ acceleration occurs when an object speeds up.
Answer
Positive
Answer:
E = 20.03 J
Explanation:
Given that,
The amount of charge that passes through the filament of a certain lightbulb in 2.00 s is 1.67 C,
Voltage, V = 12 V
We need to find the energy delivered to the lightbulb filament during 2.00 s.
The energy delivered is given by :
. ....(1)
As,
As per Ohm's law, V = IR
Using formula (1).
So, the energy delivered to the lightbulb filament is 20.03 J.
Answer:
1-An object's velocity will change if a net force acts on the object. (True)
2-In order not to slow down, a car moving at a constant velocity needs a small net force applied. (False)
3- The net force which acts on an object which remains at rest is zero. (True)
4- If an object's speed does not change, no net force is acting on the object.(True)
5- If two objects are under the influence of equal forces, they have the same acceleration. (False)
6- During the collision of a car with a large truck, the truck exerts a greater force on the car than the car exerts on the truck.(False) (Newton Third Law)
Answer:
D. 803 lbs
Explanation:
In order to find the compressive stress on all three blocks we first need to find the normal surface area of each:
Surface Area of 1 Block = 3.5 x 3.5
Surface Area of 1 Block = 12.25
Surface Area of all 3 Blocks = A = 3 x 12.25
Area = 36.75
Now, the stress is given by the following formula:
Stress = Force/Area
Stress = 29500 lbs/36.75
Stress = 802.72 lbs
Hence, the correct option will be:
<u>D. 803 lbs</u>
